77  - 


MEMCAL 


GIFT  OP  DR.  P. T. GREEN 
TO  THE  COLLEGE  OF  PHARMACY 


A  MANUAL 


OF 


QUALITATIVE  ANALYSIS 


AND    OF 


CLINICAL  MEDICAL  CHEMISTRY, 


FOB 


PHYSICIANS  AND  STUDENTS. 


BY 

CHARLES  EJ,ATT,  M.  D.,  PH.  D., 

FELLOW  OP  THE    CHEMICAL    SOCIETYOF.  LONDON,  MEMBER  OF    THE    AMERICAN  CHEMICAL 

SOCIETY,   MEMBER  OF  THE  SOCIETE  CHIM1QUE    DE  PARIS,  HONORARY  FELLOW  OF 

THE  SOCIETY  OF  BIOLOGICAL  CHEMISTRY. 


THIRD  EDITION 

REVISED  AND  ENLARGED. 


PHILADELPHIA  j 

JOHN  jos.  MCVEY; 

1900. 


COPYRIGHT,  1900, 
BY  JOHN  JOS.  MoVEY. 


T7l 


PREFACE  TO  THE  THIRD  EDITION. 


THE  success  of  preceding  editions  has  rendered  any  material 
alterations  in  plan  unadvisable.  In  the  present  rewriting,  how- 
ever, the  scope  of  the  work  has  been  enlarged  by  several  added 
chapters,  as  well  as  by  numerous  minor  additions  throughout. 
Statements  and  tests  already  presented  have  been  critically  exam- 
ined, and,  where  necessary,  revised. 

As  it  now  stands,  the  book  presents  a  synopsis  of  the  Non- 
Metals,  an  outline  of  Qualitative  Analysis  with  analytical  schemes 
for  both  simple  salts  and  complex  mixtures,  tests  for  the  Alkaloids, 
the  principles  of  Volumetric  Quantitative  Analysis,  a  section  on 
the  three  organic  classes  of  chief  physiological  interest — the  Carbo- 
hydrates, the  Proteids,  and  the  Fats,  with  a  brief  description  of 
Ferments  and  Fermentation.  The  clinical  section  of  the  book 
treats  of  the  Blood,  the  Urine,  the  Sweat,  the  Saliva,  the  Gastric 
Fluid,  the  Pancreatic  Fluid,  the  Intestinal  Fluid,  Bile,  Milk, 
and  Water.  This  section  is  written  in  more  detail,  and  includes, 
with  the  clinical  tests  possible  with  limited  laboratory  equipment, 
some  of  the  more  elaborate  and  exact  methods  used  in  advanced 
research.  The  Appendix,  together  with  tables  of  Weights  and 
Measures,  contains  a  list  of  the  Acid  Radicals,  a  list  of  the  Common 
Salts  arranged  according  to  solubility,  a  list  of  Reagents,  with 
formulae  and  methods  of  preparation,  and,  finally,  a  complete  list 
of  the  Poisons  and  Methods  of  Treatment. 

For  valuable  suggestions  I  am  indebted  to  my  friends:  Joseph 

C.  Guernsey,  A.  M.,  M.  D.,  and  Raymond  J.  Harris,  A.  M.,  M.  D., 
of  Philadelphia,  to  A.  B.  Griffiths,  Ph.  D.,  F.  R.  S.  E.,  of  London, 
and  to  E.  W.  Carlier,  M.  D.,  D.  Sc.,  and  T.  H.  Milroy,  M.  D. ; 

D.  Sc.,  of  the  University  of  Edinburgh. 

C.  P. 
222  N.  BROAD  STREET, 

PHILADELPHIA. 


r 


CONTENTS 


PART  I.— QUALITATIVE  ANALYSIS. 

Table  of  Elements 8 

Non-Metals 9 

Metals 14 

Analytical  Scheme  for  Metals 25 

Scheme  of  Examination  for  a  Single  Metal    .   .  29 

Tests  for  the  Common  Acids 30 

General  Plan  of  Analysis    .   .          36 

Special  Tests— Arsenic,  Antimony,  Mercury, 
Alcohol,  Chloral,  Chloroform,  Ether,  Formal- 
dehyde, Glycerol,  Hydrogen  dioxide,  Phenol.  41 

Tests  for  the  Alkaloids 46 

Glucosides,  Ptomaines,  and  Leucomaines  ...  53 
Separation  of  Metals  and  Alkaloids  from  Or- 
ganic matter ....  53 

VOLUMETRIC  QUANTITATIVE  ANALYSIS 57 

PART  II.— CARBOHYDRATES 69 

PROTEIDS 76 

FATS  AND  OILS 84 

FERMENTS  AND  FERMENTATION 87 

PART  III.— CLINICAL. 

Blood,  Composition 91 

Examination  of  Blood 95 

Tests  for  Blood 97 

Urine,  Composition         99 

Clinical  Analysis  of  Urine 100 

Urinary  Sediments 123 

Urinary  Calculi 127 

Sweat 129 

Saliva 130 

Gastric  Fluid,  Composition 131 

Clinical  Analysis 132 

Tests  for  Rate  of  Absorption  and  Motor 

Function 133 

Artificial  Digestion 134 

Pancreatic  Fluid 135 

Intestinal  Fluid 136 

(v) 


vi  CONTENTS. 

PAGE 

PART  III.— CLINICAL.— Continued. 

Bile,  Composition  and  Tests 137 

Biliary  Concretions 138 

Milk,  Composition 139 

Recognition  of  Constituents 140 

Clinical  Analysis 141 

Detection  of  Adulterants 143 

Water,  Methods  of  Analysis  .... 145 

Interpretation  of  Results 149 

Examples  of  Water  Analyses 151 

APPENDIX. 

Weights  and  Measures 155 

List  of  Acid  Radicals 157 

Table  of  Solubilities 158 

List  of  Reagents 160 

List  of  Poisons,  with  Methods  of  Treatment 165 

Index  .  173 


PART  I. 


QUALITATIVE  ANALYSIS 


AND 


VOLUMETRIC  QUANTITATIVE  ANALYSIS. 


TABLE  OF  THE  ELEMENTS. 


Names  and  Symbols 

Atomic  Weights. 

Names  and  Symbols 

Atomic  Weights. 

with 

with 

Common  Valence. 

Common  Valence. 

B.P.* 

U.S.P.f 

F.W.C.J 

B.P.* 

U.S.P.f 

F.W.C.J 

Aluminum,      Al2Ti 

27.0 

27.04 

27.1 

Manganese,      Mn«,Mn2vi 

55.0 

54.8 

55.0 

Antimony,       !Sbm 

180.0 

119.6 

120.4 

Mercury,           Hg2",Hg" 

200.0 

199.8 

200.0 

Arsenic,            Asm 

75.0 

74.9 

75.0 

Molybdenum,  Movi 

96.0 

95.9 

9(i.O 

Barium.            Han 

13(5.8 

136.'.-) 

187.4 

Nickel,              Ni-i 

58.6 

58.6 

58.70 

Bismuth,          Bim 

2(#.o 

208.9 

208.1 

Nitrogen,         Nnr,  v 

14.0 

14.01 

14.04 

Boron,              Bm 

11.0 

10.9 

11.0 

Osmium,           Os«v 

185. 

190.3 

191.0 

Bromine,          Bn 

80.0 

79.76 

79.95 

Oxygen,            O" 

16.0 

15.96 

16.0 

Cadmium,       Cdu 

11-2.0 

111.5 

11-2.4 

Palladium,       Pdiv 

106.2 

10(i.35 

107.0 

Caesium,           CM 

183.0 

132.7 

132.9 

Phosphorus,    P»'.  v 

31.0 

30  96 

310 

Calcium,           Can 

40.0 

39.91 

40.1 

Platinum,         Pt" 

191.4 

194.3 

194.9 

Carbon,          (  ».  "• 

1-2.0 

11.97 

1-2.0 

Potassium,       KI 

39.0 

39.03 

39.11 

Cerium,            Cem 

141.5 

139.9 

139.0 

Rubidium,        Rbi 

85.4 

85.2 

85.4 

Chlorine,          Cl» 

35.5 

35.37 

35.45 

Selenium,          Seiv 

78.9 

78.87 

79.2 

Chromium,      Cm,Cravi 

5-2.5 

52.0 

52.1 

Silicon,              Siiv 

28.0 

28.8 

28.4 

Cobalt,              Con 

BS.« 

58.6 

59.0 

Silver,               Agi 

108.0 

107.66 

107.92 

Columbian!,    Cbv 

94.0 

93.7 

93.7 

Souium,             Nai 

23.0 

23.0 

23.05 

Copper,            CUfUfCw 

63.3 

63.18 

63.6 

Strontium,       Sm 

87.5 

87.3 

87.6 

Fluorine,          F* 

19.0 

19.0 

19.05 

Sulphur,           S",  IT 

32.0 

31.98 

32.07 

Gold,                  Aui,  in 

197.0 

196.7 

197.2 

Tellurium,       Te»,  IT 

125.0 

125.0 

127.5 

Hydrogen,       HI 

1.0 

1.0 

1.008 

Tin,                     Sim,  iv 

118.0 

118.8 

119.0 

Iodine,              li 

127.0 

12653 

126.85 

Titanium,         Tiiv 

48.0 

48.6 

48.15 

Iridium,           II-IT 

193.0 

192.5 

193.1 

Tungsten,         WTI 

184.0 

183  6 

184.0 

Iron,                  Fen,Fe~Ti 

56.0 

55.88 

B6.0 

Uranium,          UTI 

240.0 

238.8 

239.6 

Lead,                Pb« 

206.4 

206.4 

206.92 

Vanadium,        Vv 

51.0 

51  1 

51.4 

Lithium,          Lii 

7.0 

7.01 

7.03 

Zinc,                    Znn 

64.9 

65.1 

65.4 

Magnesium,    Mg« 

24.0 

24.3 

24.3 

Zirconium,       ZIIT 

90.4 

1)0.4 

90.4 

In  addition  to  the  above  may  be  mentioned  Argon,  A,  Beryllium,  Be  (also  known  as  Glucinum, 
Gl),  Erbium,  Er,  Gadolinium,  Gd,  Gallium,  Ga,  Germanium,  Ge,  Helium,  He,  Indium,  In,  Lantha- 
num, La,  Neodidymium,  Nd,  Praseodidymium,  Pr,  Rhodium,  Rh,  Ruthenium,  Ru,  Samarium, 
Sm,  Scandium,  Sc,  Tantalum,  Ta,  Terbium,  Tb,  Thallium,  Tl,  Thorium,  Th,  Thulium,  Tu,  Ytter- 
bium, Yb,  Yttrium,  Yt. 

Columbium,  named  in  the  list,  is  also  known  as  Niobium,  Nb. 

*  British  Pharmacopeia,  H=l,  O  =  16. 

t  United  States  Pharmacopoeia,  H  =  1.    Atomic  weights  after  Meyer  and  Seubert. 

I  F.  W.  Clarke.  Report  of  Committee  of  American  Chemical  Society.  See  J  ournal  of  the  Ameri- 
can Chemical  Society,  February,  1900.  O  =  16. 

(viii) 


THE  NON-METALS.* 


HYDROGEN. 

Prepared.  1.)  By  the  action  of  zinc  on  sulphuric  acid.  2.)  By 
the  action  of  sodium  on  water.  3. )  By  the  electrolytic  decompo- 
sition of  water.  Properties.  Colorless,  odorless,  tasteless  gas. 
Lightast  substance  known.  Is  inflammable,  burning  with  a  pale 
bluish  flame.  The  mixture  with  air  is  explosive. 

OXYGEN. 

Prepared.  1.)  By  heating  mercuric  oxide.  2.)  By  heating 
potassium  chlorate,  best  after  addition  of  a  little  manganese  diox- 
ide. Properties.  Colorless,  odorless,  tasteless  gas,  a  little  heavier 
than  air,  only  slightly  soluble  in  water.  It  is  incombustible,  but 
is  a  supporter  of  combustion.  It  unites  readily  with  most  other 
elements  forming  oxides;  with  non-metals,  acid  oxides,  with 
metals,  basic  oxides. 

OZONE,  03  (Oxygen,  02),  Prepared.  1.)  By  moistening  a 
mixture  of  potassium  permanganate  and  barium  dioxide  with  sul- 
phuric acid.  2.)  By  the  slow  oxidation  of  moist  phosphorus. 
3.)  By  electric  discharge  through  air  or  oxygen.  Properties.  A 
gas  with  characteristic  odor,  an  oxidizing  agent,  soluble  in  oils. 
A  paper  impregnated  with  starch  and  potassium  iodide  becomes 
blue  when  exposed  to  the  gas. 

WATER.  May  be  made  by  burning  hydrogen  in  air,  by  explod- 
ing a  mixture  of  hydrogen  and  oxygen,  by  the  reaction  between  a 
true  base  and  a  true  acid.  It  may  be  decomposed  by  high  temper- 
atures and  by  electrolysis.  It  is  purified  by  sedimentation,  by 
filtration,  by  boiling,  and  by  distillation.  A  water  has  a  ''tem- 
porary hardness"  when  it  contains  carbonates  of  calcium  and 

*  The  division  into  Non-Metals  and  Metals  in  this  book  is  based  upon  the  part 
played  by  the  various  elements  in  chemical  analysis.  For  this  reason  arsenic, 
antimony,  and  bismuth,  ordinarily  regarded  as  non-metals,  are  here  classed  with 
the  metals  and  grouped  with  copper,  tin,  mercury  and  cadmium. 

(9) 


10  QUALITA TIVE  ANAL YSIS. 

magnesium;  it  has  a  "permanent  hardness"  when  it  contains  the 
sulphates  of  the  same  elements. 

HYDROGEN  DIOXIDE.  Prepared.  By  the  action  of  an  acid  on 
barium  dioxide.  Properties.  A  colorless  liquid  without  odor,  but 
with  a  characteristic  taste.  The  strong  solutions  quickly  decom- 
pose, the  dilute  solutions  are  more  stable.  The  usual  strength  is 
a  three  per  cent,  by  weight  solution  giving  off  ten  volumes  of  avail- 
able oxygen.  For  tests  see  Index. 

NITROGEN.  * 

Prepared.  1.)  By  passing  air  over  incandescent  copper,  the 
metal  uniting  with  the  oxygen  present.  2. )  By  heating  ammon- 
ium nitrite.  Properties.  A  colorless,  odorless,  tasteless  gas,  a  little 
lighter  than  air,  incombustible,  a  non-supporter  of  combustion, 
does  not  support  life,  is  not  poisonous. 

AMMONIA,  NH 3.  Prepared.  1.)  By  mixing  equal  parts  of  am- 
monium chloride  and  calcium  hydroxide,  and  warming.  2. )  By 
treating  ammonium  chloride,  dry,  or  in  solution,  with  an  alkali. 
3.)  By  boiling  a  solution  of  ammonium  hydroxide.  Properties. 
A  colorless  gas  with  characteristic  odor;  will  burn  in  pure  oxygen, 
but  not  in  air;  very  soluble  in  water,  the  solution  being  known  as 
ammonium  hydroxide.  The  radical,  NH4,  ammonium,  forms 
compounds  similar  to  those  of  the  alkali  metals. 

NITROGEN  MONOXIDE,  N20.  (Nitrous  oxide).  Prepared  by  heat- 
ing ammonium  nitrate.  Properties.  A  colorless,  odorless  gas,  with 
a  faint  sweetish  taste,  producing  anesthesia  when  inhaled. 

NITROGEN  DIOXIDE,  N20 2 .     (Nitric  oxide.)     A  colorless  gas. 

NITROGEN  TRIOXIDE,  N203.  (Nitrous  anhydride. )  A  blue  liquid 
with  low  boiling  point,  with  water  forming  nitrous  acid. 

NITROGEN  TETROXIDE,  N 2 04.  (Nitrogen  peroxide.)  A  colorless 
liquid  at  low  temperatures;  at  higher  temperatures  a  reddish -brown 
gas,  2N02. 

NITROGEN  PENTOXIDE,  N205.  (Nitric  anhydride. )  A  crystalline 
substance  forming,  with  water,  nitric  acid.  Practically  nitric  acid 
is  made  by  treating  sodium  nitrate  with  sulphuric  acid. 

ATMOSPHERE.  The  essential  ingredients  of  the  atmosphere  are 
Nitrogen,  about  77.5  per  cent.;  Oxygen,  20.6  per  cent.;  Carbon 
dioxide,  0.03-0.04  per  cent.;  Aqueous  vapor,  0.5-1.4  per  cent. 
Other  ingredients  may  be  styled  accidental.  The  carbon  dioxide 

*  Tests  for  compounds,  see  Index. 


THE  NON-METALS.  11 

and  water  may  be  estimated  by  passing  a  measured  volume  of  air 
through  two  weighed  tubes,  the  first,  containing  calcium  chloride, 
absorbs  water,  the  second,  containing  potassium  hydroxide,  ab- 
sorbs carbon  dioxide.  From  the  increase  in  weight  of  the  tubes 
the  amounts  of  carbon  dioxide  and  water  in  the  air  may  be  calcu- 
lated. 

THE  HALOGEN  ELEMENTS.* 

FLUORINE.  Fluorine  is  rare  in  the  free  state.  The  acid  of  fluor- 
ine, Hydroflouric  acid,  HF,  may  be  made  by  treating  powdered 
calcium  fluoride  with  sulphuric  acid.  It  is  a  powerful  corrosive, 
attacks  glass,  and  is  used  in  etching  of  glass.  Vapors  are  dangerous. 

CHLORINE.  Prepared.  1.)  By  the  action  of  sulphuric  acid  and 
manganese  dioxide  on  sodium  chloride.  2.)  By  action  of  hydro- 
chloric acid  on  manganese  dioxide.  Properties.  A  yellowish-green 
gas,  with  suffocating  odor,  soluble  in  water  ("  chlorine  water"). 
Its  mixture  with  hydrogen  explodes  when  exposed  to  the  light. 
Acts  as  an  oxidizing  agent  and  bleach. 

Hydrochloric  acid  is  prepared  by  the  action  of  sulphuric  acid  on 
sodium  chloride. 

BROMINE.  Prepared,  by  the  action  of  sulphuric  acid  and  manga- 
nese dioxide  on  potassium  bromide.  Properties.  A  dark  reddish- 
brown,  volatile  liquid,  giving  off  pungent,  irritating  fumes.  It  is 
slightly  soluble  in  water,  forming  "bromine  water." 

Hydrobromic  acid  may  be  made  by  the  action  of  water  on  phos- 
phorus tribromide. 

IODINE.  Prepared,  by  the  action  of  sulphuric  acid  and  manga- 
nese dioxide  on  potassium  iodide.  Properties.  It  is  a  crystalline 
substance,  volatile,  giving  off  violet-colored  vapors  with  a  pungent 
odor.  It  is  very  slightly  soluble  in  pure  water,  but  is  soluble  in 
water  containing  potassium  iodide,  and  in  alcohol  and  in  chloro- 
form. 

Hydriodic  acid  may  be  made  by  the  action  of  water  on  phos- 
phorus tri-iodide. 

PHOSPHORTJS.  * 

Prepared,  from  tricalcic  phosphate,  Ca3(P04)2;  this  substance  is 
converted  into  phosphoric  acid  and  the  latter  is  then  reduced  by 
heating  with  carbon.  Properties.  Two  varieties.  Ordinary  Phos- 
phorus is  a  waxy  semi-transparent  solid  with  characteristic  odor, 

*  Tests  for  compounds,  see  Index. 


12  QUALITATIVE  ANALYSIS. 

giving  off  luminous  fumes.  It  oxidizes  on  exposure  to  air,  is  kept 
under  water,  is  soluble  in  carbon  disulphide  and  in  oils,  and  is 
strongly  poisonous. 

Red  or  Amorphous  Phosphorus  is  made  by  heating  the  ordinary 
variety  for  several  days  in  a  closed  tube,  It  is  a  red  amorphous 
powder,  does  not  give  off  fumes,  is  not  luminous  in  the  dark,  is 
not  soluble  in  carbon  disulphide,  nor  in  oils,  and  is  not  poisonous. 

SULPHUR.* 

Prepared,  by  refining  the  crude  sulphur  of  nature.  Properties. 
Ordinary  sulphur  is  a  yellow  brittle  solid,  or  a  fine  yellow  powder, 
insoluble  in  water,  very  slightly  soluble  in  alcohol,  soluble  in  car- 
bon disulphide.  It  melts  when  heated,  and,  in  the  air,  burns  to 
sulphur  dioxide. 

HYDROGEN  SULPHIDE,  or  Hydrosulphuric  acid,  is  prepared  by 
the  action  of  an  acid,  preferably  hydrochloric  acid  on  ferrous  sul- 
phide. It  is  an  inflammable  gas,  with  characteristic  odor,  used  in 
chemical  analysis. 

SULPHUR  DIOXIDE,  S02.  Prepared,  by  burning  sulphur.  It  is 
a  colorless  gas  with  suffocating  odor;  it  is  soluble  in  water  forming 
sulphurous  acid. 

SULPHUR  TRIOXIDE,  S03.  Prepared,  by  oxidation  of  sulphur 
dioxide,  is  generally  in  crystal  form.  Dissolved  in  water  it  gives 
sulphuric  acid. 

CARBON.* 

Occurs  in  nature  in  three  allotropic  forms,  the  clear  isometric 
crystal  diamond,  the  black  hexagonal  crystal  graphite,  and  the 
amorphous  variety  as  found  in  soot,  charcoal,  etc.  Carbon  resists 
the  action  of  many  ordinary  reagents,  but  at  high  temperatures  it 
has  a  strong  affinity  for  oxygen  and  is  therefore  a  valuable  reduc- 
ing agent. 

CARBON  MONOXIDE,  CO  (Carbonic  oxide).  Prepared.  1.)  By 
burning  carbon  with  an  insufficient  supply  of  oxygen.  2.)  By 
warming  a  mixture  of  1  part  crystalline  potassium  ferrocyanide 
and  10  parts  of  strong  sulphuric  acid.  Properties.  A  colorless, 
odorless  gas,  very  slightly  soluble  in  water,  a  non-supporter  of 
combustion.  Heated  in  the  air  it  burns  with  a  pale  bluish  flame. 
It  is  strongly  poisonous. 

*  Tests  for  compounds,  see  Index. 


THE  NON-METALS.  13 

CARBON  DIOXIDE,  C02  (Carbonic  anhydride).  Prepared.  1.) 
By  heating  calcium  carbonate.  2. )  By  treating  carbonates  with 
acids.  Properties.  It  is  a  colorless  gas,  generally  with  a  faint  acid 
odor,  soluble  in  water,  a  non-supporter  of  combustion,  and  incom- 
bustible. It  will  not  support  life  but  is  non-poisonous.  Carbonic 
acid,  H2C03,  may  be  regarded  as  the  compound  of  carbon  dioxide 
and  water. 

SILICON.* 

The  element  is  obtained  in  both  crystalline  and  amorphous 
forms  but  does  not  occur  in  tl.  e  free  state  in  nature. 

SILICON  DIOXIDE,  Si02  (Silica).  Occurs  in  nature  as  rock  crystal, 
agate,  quartz  sand,  etc.  It  is  a  hard,  infusible  substance,  not  at- 
tacked by  ordinary  acids,  but  dissolves  in  hydrofluoric  acid,  and 
is  decomposed  by  fusion  with  alkali  carbonates.  The  Silicates  are 
salts  of  silicic  acids,  H4Si04,  H2Si03,  etc. 

BORON.* 

Rare  as  an  element.  Boric  acid,  H3B03,  is  a  crystalline  sub- 
stance, slightly  soluble  in  water,  more  soluble  in  alcohol.  Other 
compounds  are,  Boric  anhydride,  B203,  Metaboric  acid,  HB02, 
Tetraboric  acid,  H2B407.  The  sodium  salt  of  tetraboric  acid  is 
known  as  Borax. 

*  Tests  for  compounds,  see  Index. 


THE  METALS. 


CLASSIFICATION  FOR  PURPOSES  OF  ANALYSIS. 

THE  metals  are  commonly  divided  into  five  groups,  according  to 
their  behavior  with  certain  general,  or  group  reagents;  as  follows: 

GROUP  I. — Metals  forming  chlorides  insoluble  in  water,  and  con- 
sequently precipitated  from  solutions  of  their  salts  by  Hydro- 
chloric Acid.  Lead,  Silver,  Mercury  (Mercurous). 

GROUP  II. — Metals  forming  sulphides  insoluble  in  water  and  in 
dilute  acids,  precipitated  from  solutions  of  their  salts  by  Hydrogen 
Sulphide. 

(a)  Sulphides  soluble  in  Ammonium  Sulphide  and  in  Sodium 

or  Potassium  Hydroxides.    Arsenic,  Antimony,  Tin,  Gold,  Platinum. 

'  (b)  Sulphides  insoluble  in  Ammonium  Sulphide  and  in  Sodium 

or  Potassium  Hydroxides.     Mercury  (Mercuric),  Bismuth,  Copper, 

Cadmium. 

GROUP  III. — Metals  forming  sulphides  and  hydroxides,  which  are 
decomposed  by  acids,  but  which  are  insoluble  in  water,  precipi- 
tated from  neutral  solutions  by  Ammonium  Sulphide.  Iron, 
Manganese,  Aluminum,  Chromium,  Cobalt,  Nickel,  Zinc. 

GROUP  IV. — Metals  forming  sulphides  soluble  in  water  or  de- 
composed by  dilute  acids,  but  whose  carbonates  are  insoluble,  pre- 
cipitated from  solutions  of  their  salts  by  Ammonium  Carbonate. 
Barium,  Strontium,  Calcium  (Magnesium}. 

GROUP  V. — Metals  forming  chlorides,  sulphides,  and  carbonates 
soluble  in  water,  and  not  precipitated  by  the  preceding  group 
reagents.  Potassium,  Sodium,  Lithium.  (The  basic  radical  Am- 
monium, NH4,  is  commonly  included  with  this  group.) 

TESTS  FOR  THE  METALS. 
GROUP  V.     The  ' '  Alkali  Group. ' ' 

Potassium,  K,  Sodium,  Na,  Lithium,  Li,  (Ammonium,  NH4). 

POTASSIUM. 

(Use  KC1,  Solution  or  Solid.) 
l.-^Test  on  clean  platinum  wire,  in  Bunsen  flame,  observe  the 

(14) 


TESTS  FOR  THE  METALS.  15 

violet  color  developed.  In  presence  of  sodium  compounds  the 
yellow  rays  produced  thereby  may  be  excluded  by  use  of  blue 
glass. 

2.  — PtCl4  precipitates  from  solutions  of  potassium  salts,  yellow 
crystalline,  potassium  platinic  chloride,  K2PtCl6,  soluble  in  excess 
of  water  and  in  alkalies  but  insoluble  in  acids  or  in  alcohol. 

3.— H2C4H4O6  precipitates  from  concentrated  neutral  solutions 
of  potassium  salts,  white,  crystalline,  potassium  hydrogen  tartrate, 
KHC4H406. 

Potassium  hydroxide,  caustic  potash,  has  no  odor,  has  a  peculiar  "  soapy  feel," 
and,  with  solution  of  mercuric  chloride,  gives  an  orange-yellow  precipitate. 

Potassium  carbonate  is  similar,  but  may  be  recognized  by  the  effervescence  with 
acids. 

SODIUM. 

(Use  NaCl,  Solution  or  Solid.) 

1. — Test  on  platinum  wire,  in  Bunsen  flame,  observe  the  bright 
yellow  color  developed. 

2. — Potassium  pyroantimonate,  H2K2Sb207,  precipitates  from 
concentrated  solutions  of  sodium  salts,  a  white,  crystalline,  sodium 
pyroantimonate  H2Na2Sb207. 

3. — Neither  PtCl4,  nor  H2C4H406,  give  precipitates  with  sodium 
salts.  Compare  Potassium  and  Ammonium. 

Sodium  hydroxide,  caustic  soda,  has  no  odor,  has  a  peculiar  a  soapy  feel,"  and, 
with  solution  of  mercuric  chloride,  gives  an  orange-yellow  precipitate. 

Sodium  carbonate  is  similar,  but  may  be  recognized  by  the  effervescence  with 
acids. 

LITHIUM. 
(UseLiCl,  Solution.) 

1. — Lithium  compounds  color  the  non-luminous  flame  crimson, 
or  carmine  red. 

2. — Na2HP04  precipitates  from  hot  solutions  of  lithium  salts, 
lithium  phosphate,  Li3P04,  best  after  addition  of  NaOH. 

3. — Na2C03  precipitates,  from  cold  concentrated  solutions 
Li  2  CO  3,  soluble  in  100  parts  of  water. 

4. — PtCl4  and  H2C4H406  give  no  precipitates. 

AMMONIUM. 

(UseNH4OH  and  (NH4)2SO4.) 
1.— Note  the  odor  of  NH4OH. 

2. — Note  the  action  of  the  fumes  on  red  litmus  paper. 
3. — Upon  one  watch-glass  place  a  drop  of  NH4OH,  upon  another 


1 6  Q UALITA  TIVE  ANAL  YSIS. 

a  drop  of  HC1.  Observe  the  white  fumes  of  NH4C1  produced  when 
the  glasses  are  brought  together. 

4. — Test  a  solution  of  (NH4)2S04.  Note  that  no  odor  is  given 
off.  Add  a  few  drops  of  NaOH,  and  heat.  Note  the  character- 
istic odor  of  ammonia. 

5. — When  a  powder  is  to  be  tested,  mix  a  little  of  it  with 
Ca(OH)2  on  a  watch  glass;  moisten  with  water  and  cover  with  a 
second  watch  glass,  to  the  inner  side  of  which  is  adherent  a  piece 
of  red  litmus  paper.  The  presence  of  an  ammonium  compound 
will  be  shown  by  the  litmus  paper  turning  blue. 

6. — PtCl4,  and  H2C4H406  produce  precipitates  with  ammonium 
salts  resembling  those  produced  from  solutions  of  potassium  com- 
pounds. 

Ammonium  hydroxide  has  a  characteristic  odor,  and  gives  a  white  precipitate 
with  solutions  of  mercuric  chloride. 

Ammonium  carbonate  is  similar,  but  may  be  recognized  by  the  effervescence  with 
acids. 

For  the  separation  of  members  of  this  group,  see  p.  29. 

GROUP  IV.     Metals  of  the  "Alkaline  Earths." 
Barium,  Ba,  Strontium,  Sr,  Calcium,  Ca,  Magnesium,  Mg. 

BARIUM. 
(Use  BaCl2,  Solution.) 

1. — (NH4)2C03  precipitates  white  barium  carbonate,  BaC03. 

2. — H2S04  (dil.)  and  all  soluble  sulphates  precipitate  white  bar- 
ium sulphate,  BaS04,  insoluble  in  boiling,  ammoniacal 
(NH4)2S04. 

3. — Na2HP04  precipitates  white  barium  phosphate,  BaHP04, 
soluble  in  HC2H802. 

4. — K2Cr04  and  K2O207  precipitate  yellow  barium  chromatc, 
BaO04,  insoluble  in  dilute  HC2H3O2  but  soluble  in  HC1. 

5. — Barium  compounds  impart  a  green  color  to  the  flame. 

STRONTIUM. 

(Use  Sr(NO3)2,  Solution.) 

1. — (NH4)2C03  precipitates  white  strontium  carbonate,  SrC03. 

2. — H2S04  (dil.)  and  soluble  sulphates  precipitate  white  stron- 
tium sulphate,  SrS04,  insoluble  in  boiling,  ammoniacal 
(NH,),S04. 

3. — K2OO4  precipitates,   slowly,    from    strong    alkaline   solu- 


TESTS  FOE  THE  METALS.  17 

tions,  yellow  strontium  chromate,  SrCr04,  soluble  in  HC2H302. 
K2Cr207  gives  no  precipitate. 

4. — Strontium  compounds  impart  an  intense  red  or  crimson 
color  to  the  flame. 

CALCIUM. 

(Use  CaCl2,  Solution.) 

1. — (NH4)2C03  precipitates  white  calcium  carbonate,  CaC03 
from  ordinary  but  not  from  highly  dilute  solutions. 

2. — From  strong  solutions  H2S04  precipitates  white  calcium  sul- 
phate, CaS04,  soluble  in  an  excess  of  water  and  in  boiling,  am- 
moniacal  (NH4)2S04. 

3. — Na2HP04  precipitates  white  calcium  phosphate,  CaHP04, 
soluble  in  HC2H302. 

4. — (NH4)2C204  precipitates  white  calcium  oxalate,  CaC204, 
soluble  in  HC1,  insoluble  in  HC2H3O2. 

5. — Calcium  compounds  impart  a  yellowish-red  color  to  the 
flame. 

MAGNESIUM. 

(Use  MgCl.,  Solution.) 

1. — (^H-.)2C03  precipitates,  slowly,  from  strong  solutions, 
white  magnesium  carbonate,  MgCO3.  The  precipitation  is  hast- 
ened by  warming,  but  is  prevented  by  presence  of  NH4C1. 

2. — NH4OH  precipitates  part  of  the  magnesium  as  Mg(OH)2, 
but  the  precipitation  is  prevented  by  presence  of  NH4C1,  and, 
also,  by  too  great  dilution.  NaOH  gives  a  more  complete  precipi- 
tation. 

3. — Na2HPO4,  in  presence  of  NH4C1  and  NH4OH,  precipitates 
crystalline  NH4MgP04.  In  dilute  solutions  the  precipitate  forms 
slowly. 

4. — Neither  H2S04  nor  K2Cr04  precipitate  salts  of  magnesium 

For  the  separation  of  members  of  this  group,  see  pages  28  and  29. 

GROUP  III. 

Aluminum,  Al,  Chromium,  Cr,  Iron.  Fe,  Nickel,  Ni,  Cobalt,  Co, 
Manganese,  Mn,  Zinc,  Zn. 

ALUMINUM. 
(Use  Solution  of  A12C16. ) 

1. — NH4OH  precipitates  white  aluminum  hydroxide,  A12(OH)6, 
insoluble  in  moderate  excess. 


18  QUALITATIVE  ANALYSIS. 

2. — NaOH  precipitates  white  aluminum  hydroxide,  A12(OH)6. 
Soluble  in  excess  of  the  reagent,  but  reprecipitated  by  boiling  with 
excess  of  NH4C1. 

3.— Both  (NH4)2S  and  (NH4)2C03  precipitate  white  alumi- 
num hydroxide,  A12(OH)6. 
A12C16  4-  3(NH4)2S  +  6H20  =  A12(OH)6  -f-  6NH4C1  +  3H2S. 

4. — Na2HP04,  in  presence  of  sodium  acetate,  precipitates  alu- 
minum phosphate,  A12(P04)2.  The  precipitate  is  soluble  in 
sodium  or  potassium  hydroxide,  in  HC1,  or  in  HN03;  it  is  insol- 
uble in  NH4OH,  NH4C1,  or  in  HC2H302. 

5. — Heated  in  the  borax  bead  a  clear  glass  is  obtained. 

CHROMIUM. 

(Use  Cr2Cl6  Solution. ) 

1. — NH4OH  precipitates  light  green  chromium  hydroxide,. 
Cr2(OH)6. 

2. — NaOH  precipitates  light  green  chromium  hydroxide,. 
Cr2(OH6).  Soluble  in  excess  but  precipitated  again  on  boiling. 

3.— (NH4)2S  precipitates  light  green  chromium  hydroxide,. 
Cr2(OH)6. 

4. — Fused  with  a  mixture  of  KN03  and  Na2C03  on  platinum 
foil,  yellow  sodium  and  potassium  chromates  are  formed,  soluble 
in  water. 

5. — Acidify  the  solution  obtained  in  the  last  test,  with  HC2- 
H3O2  and  then  add  Pb(C2H302)2— a  yellow  precipitate  of  lead' 
chromate,  PbCr04,  is  formed. 

6. — Borax  bead;  oxidizing  flame  (0.  F. )  yellow  or  reddish  when 
hot,  yellow-green  when  cold.  Reducing  flame  (R.  F. )  green,  hot 
and  cold. 

Tests  for  chromates,  seep.  32. 

IRON. 

FERROUS  COMPOUNDS.     (Use  FeSO4  Solution. ) 

1. — NaOH  or  NH4OH  precipitates  white,  or  greenish-white,. 
Fe(OH)2,  turning  brown  on  exposure  to  the  air. 

2.— (NH4)2S  precipitates  black  ferrous  sulphide,  FeS. 
3. — K4Fe(CN)6    precipitates    bluish-white    potassium    ferrous 
ferrocyanide,  K2Fe2(CN)6. 

4. — K3Fe(CN)6  precipitates  dark  blue  ferrous  ferricyanider 
Fe5(CN)12,  known  as  Turnbull's  blue. 


TESTS  FOE  THE  METALS. 


19 


5. — K(CN)S  gives  no  reaction. 

FERRIC  COMPOUNDS.     (Use  Fe2CJ6  Solution.) 

1. — NaOH  or  NH4OH  precipitates  reddish-brown  ferric  hydrox- 
ide, Fe2(OH)6. 

2. — (NH4)2S  precipitates  black  ferrous  sulphide,  FeS. 

3.— K4Fe(CN)6  precipitates  ferric  ferrocyanide,  Fe7(CN)18, 
known  as  Prussian  Blue. 

4. — K3Fe(CN)6  produces  no  precipitate  but  imparts  a  green  or 
brown  color  to  the  solution. 

5. — K(CN)S  produces  a  blood-red  color  due  to  the  formation  of 
ferric  sulphocyanate,  Fe2(CNS)6.  The  color  is  destroyed  by  ad- 
dition of  HgCl2. 

6. — Borax  bead  ;  0.  F.  yellow  or  yellow-red  when  hot,  yellow 
when  cold.  R.  F.  bottle  green. 

MANGANESE. 

(Use  MnSO4  Solution.) 

1. — NaOH  or  NH4OH  precipitates  whitish  manganous  hydrox- 
ide, Mn(OH)2,  turning  brown  and  oxidizing,  on  exposure  to  the 
air,  to  Mn2(OH)6.  The  precipitation  by  NH4OH  is  prevented  by 
presence  of  NH4C1. 

2. — (NH4)2S  precipitates  flesh  colored  manganous  sulphide, 
MnS. 

3. — Fused  with  a  mixture  of  KN03  and  Na2C03,  on  platinum 
foil,  green  potassium  and  sodium  manganates  are  formed. 

4. — Borax  bead ,  0.  F.  violet  when  hot,  reddish-violet  when 
cold.  R.  F.  colorless. 

5. — With  manganic  compounds  (use  solution  of  Mn2Cl6)  alka- 
line hydroxides  precipitate  brown  Mn2(OH)6.  (NH4)2S  pre- 
cipitates MnS,  as  with  manganous  compounds. 

Tests  for  permanganates,  seep.  33. 

ZINC. 

(Use  ZnSO4,  or  ZnCl2,  Solution. ) 

1. — NaOH  added  carefully  precipitates  white  zinc  hydroxide, 
Zn(OH)2  easily  soluble  in  excess: 

ZnCl2  +  2NaOH  =  Zn(OH)  2  +  2NaCl. 
Zn(OH)2  +  2NaOH  =  Na2Zn02  +  2H20. 
2. — NH4OH  precipitates  white  Zn(OH)2,  soluble  in  excess. 


20  QUALITATIVE  ANALYSIS. 

3. — (NH4)2S  precipitates  white  zinc  sulphide,  ZnS,  insoluble 
in  HC2H302,  soluble  in  dilute  HC1. 

4. — Na2C03  precipitates  white,  basic  carbonate,  Zn5(OH)6- 
(C03)2,  insoluble  in  excess. 

5. — Borax  bead  ;  0.  F.  clear  yellow  glass,  colorless  on  cooling  ; 
or,  enamel-like  on  cooling,  if  present  in  excess. 

NICKEL. 

(Use  NiSO4  Solution. ) 

1. — NaOH  precipitates  pale  green  Ni(OH)2,  insoluble  in  excess 
and  unaltered  by  boiling. 

2. — NH4OH  precipitates  pale  green  Ni(OH)2,  soluble  in  excess, 
and  in  ammonium  salts,  to  a  violet-blue  solution. 

3. — (NH4)2S  precipitates  black  NiS,  insoluble  in  cold  dilute 
HC1. 

4. — Borax  bead;  0.  F.  violet  when  hot,  reddish-brown  when 
cold. 

COBALT. 
(Use  Co(NO3)2  Solution.) 

1. — NaOH  precipitates  blue  Co(OH)2,  insoluble  in  excess.  On 
boiling,  the  precipitate  becomes  pink. 

2. — NH4OH  precipitates  blue  Co(OH)2,  soluble  in  excess. 

3. — (NH4)2S  precipitates  black  CoS,  insoluble  in  cold  dilute 
HC1. 

4.— Borax  bead;  0.  F.  blue. 

For  the  separation  of  members  of  this  group,  seepages  27  and  28. 

GROUP  II. 

Arsenic,  As,  Antimony,  Sb,  Mercury  (Mercuric)  Hg,  •  Bismuth,  Bi,  Copper,  Cu, 
Cadmium,  Cd,  Tin,  Sn,  Gold,  Au,  Platinum,  Pt. 

ARSENIC. 
ARSENOUS  COMPOUNDS.     (Use  aqueous  solution  of  As2Os.) 

1. — Acidify  with  hydrochloric  acid,  and  pass  H2S  gas  through 
the  solution.  A  precipitate  of  yellow  As2S3  is  formed,  insoluble 
in  hot  HC1,  soluble  in  alkalies  and  in  alkaline  sulphides  and  car- 
bonates. 

2. — Ammonio-silver  nitrate  precipitates  yellow  silver  arsenite, 
Ag8As03,  soluble  in  excess  of  ammonium  hydroxide. 

3. — Ammonio-cupric  sulphate  precipitates  green  copper  arsenite, 
CuHAsO3,  soluble  in  excess  of  ammonium  hydroxide. 


TESTS  FOR  THE  METALS.  21 

(Use  aqueous  solution  of  Na2HAsO3.) 

4. — Test  1,  page  20,  may  be  repeated  as  described.  Tests  2  and 
3  may  be  repeated  with  ordinary  solutions  of  silver  nitrate  and  of 
copper  sulphate. 

ARSENIC  COMPOUNDS.     (Use  solution  of  As2O5. ) 

1. — H2S   gas   precipitates  slowly   from   the   acidified   solution 
(acidify  with  HC1)  arsenous  sulphide,  As2S3,  mixed  with  sulphur. 
2. — Ammonio-silver  nitrate  precipitates  brown  silver  arsenate, 
Ag3As04,  soluble  in  excess  of  ammonium  hydroxide. 

3. — Ammonio-cupric  sulphate  precipitates  bluish-green  copper 
arsenate,  CuHAs04,  soluble  in  excess  of  ammonium  hydroxide. 

(Use  solution  of  NagHAsO^ ) 

4. — Test  1  may  be  repeated  as  above.  Tests  2  and  3  may  be 
repeated  with  ordinary  solutions  of  silver  nitrate  and  of  copper 
sulphate. 

ANTIMONY. 

(Use  Tartar  Emetic  in  Solution.) 

1. — Acidify  with  HC1  and  pass  H2S  gas,  an  orange  precipitate 
of  Sb2S3  is  formed.  Soluble  in  sodium  hydroxide,  in  yellow 
ammonium  sulphide,  but  insoluble  in  alkaline  carbonates. 

2. — NaOH,  and  NH4OH  precipitate  antimonous  hydroxide, 
Sb(OH)3.  Soluble  in  excess  of  the  reagent  with  NaOH,  but  not 
with  NH4OH. 

3. — HC1  precipitates  a  white,  basic  chloride,  soluble  in  excess  of 
the  acid. 

4. — In  the  absence  of  tartaric  or  citric  acids,  e.  g.,  in  solutions 
of  the  chloride,  SbCl3,  an  excess  of  water  produces  a  precipitate 
of  a  basic  salt,  the  oxychloride,  SbOCl,  or  "  Powder  of  Algaroth." 

5. — Borax  bead;  0.  F.  clear  yellow  when  hot,  colorless  when 
cold. 

See,  also,  under  Special  Tests. 

MERCURY  (ic). 
( Use  HgCl2  Solution.) 

1. — H2S  gas  precipitates  black  mercuric  sulphide,  HgS,  insolu- 
ble in  HNO3,  HC1,  or  in  alkaline  sulphides. 

2. — NaOH  precipitates  yellow  mercuric  oxide,  HgO. 
3. — NH4OH   precipitates    white   mercur-ammonium    chloride, 
NH2HgCl. 


22  Q UALITA TIVE  ANALYSIS. 

4. — SnCl2  precipitates  white  mercurous  chloride,  Hg2Cl2. 

2  HgCl2  -f  SnCl2  =  Hg2Cl2  +  SnCl4. 
An  excess  of  the  reagent  precipitates  gray  metallic  mercury. 

HgCl2  +  SnCl2  =  Hg  +  SnCl4. 

5. — KI  precipitates  yellow  to  scarlet  mercuric  iodide,  HgI2  sol- 
uble in  excess. 

For  Mercurous  Compounds,  see  under  Group  I. ,  page  24. 
See,  also,  under  Special  Tests. 

BISMUTH. 
(Use  Bi(NO3)3  Solution.) 

1. — H2S  gas  precipitates  black  bismuth  sulphide,  Bi2S3.  Sol- 
uble in  boiling  nitric  acid,  but  insoluble  in  alkalies  and  alkaline 
sulphides. 

2. — NaOH  and  NH4OH  precipitate  white  bismuth  hydroxide, 
Bi(OH)3. 

3. — KI  precipitates  brown  bismuth  iodide,  BiI3,  soluble  in  ex- 
cess of  the  reagent. 

4. — H20  in  excess  precipitates  basic  salts  of  bismuth,  bismuth 
subnitrate,  BiON03. 

5. — Borax  bead  ;  0.  F.  with  small  amounts,  yellow  when  hot, 
colorless  when  cold.  With  larger  amounts  yellow-red  when  hot, 
yellow  when  cold. 

COPPER. 
(Use  CuSO4  Solution. ) 

1. — H2S  gas  precipitates  black  cupric  sulphide,  CuS,  soluble  in 
hot  nitric  acid,  practically  insoluble  in  alkalies  and  in  alkaline 
sulphides. 

2. — NH 4 OH  precipitates  bluish  cupric  hydroxide,  Cu(OH)2 
soluble  in  excess,  forming  a  dark  blue  solution. 

3. — NaOH  precipitates  blue  cupric  hydroxide,  Cu(OH)2,  insol- 
uble in  excess,  turning  black  on  boiling. 

4. — K4Fe(CN6)  precipitates  from  neutral  or  acid  solutions,  red- 
dish-brown cupric  ferrocyanide,  Cu2Fe(CN)6. 

5.  Copper  compounds  impart  a  green  color  to  the  Bunsen 
flame. 

6. — Borax  bead  ;  0.  F.  green  when  hot.  greenish-blue  when 
cold.  R.  F.  gives  a  colorless  bead,  red  and  opaque  on  cooling. 


TESTS  FOR  THE  METALS.  23 

CADMIUM. 
( Use  CdCla  Solution.) 

1. — H2S  precipitates  yellow  CdS,  insoluble  in  alkaline  sulphides, 
insoluble  in  KCN,  soluble  in  hot  dilute  sulphuric  acid. 

2. — NaOH  precipitates  white  Cd(OH)2,  insoluble  in  excess. 
3. — NH4OH  precipitates  white  Cd(OH)2,  soluble  in  excess. 
4.— (NH4)2S  precipitates  yellow  CdS. 

5. — Borax  bead;  0.  F.  clear  yellow  when  hot,  colorless  when 
cold. 

TIN. 

STANNOTJS  COMPOUNDS.     (Use  SnCl2  Solution.) 

1. — H2S  precipitates  brown  SnS,  soluble  in  yellow  alkaline  sul- 
phides, in  NaOH,  and  in  boiling  HC1. 

2. — NH4OH  precipitates  white  H2Sn02,  slightly  soluble  in 
excess. 

3. — HgCl2  precipitates  white  Hg2Cl2.  On  boiling,  metallic 
mercury  separates  out. 

STANNIC  COMPOUNDS.     (Use  SnCl4  Solution.) 

1. — H2S  precipitates  yellowish  SnS2,  soluble  in  yellow  alkaline 
sulphides,  in  NaOH,  and  in  boiling  HC1. 

2. — NH4OH  precipitates  white  H2Sn03,  stannic  acid,  insoluble 
in  excess. 

3. — Borax  head;  0.  F.     Colorless  glass  with  small  amounts. 

GOLD. 
(Use  AuCl,  Solution.) 

1. — H2S  precipitates  black  Au2S3  (from  hot  solutions  Au2S) 
insoluble  in  HC1  or  in  (NH4)2C03,  soluble  in  nitrohydrochloric 
acid  and  in  yellow  ammonium  sulphide. 

2. — H2C204  or  FeS04,  boiled  with  solutions  of  gold,  precipitate 
the  latter  in  the  form  of  a  dark  brown  powder. 

3.— SnCl2  or,  better,  a  mixture  of  SnCl2  with  Fe2Cl6,  precipi- 
tates mixed  oxides  of  gold  and  tin,  "  Purple  of  Cassius." 

4. — NH4OH  precipitates  reddish  ammonium  aurate,  ''fulmi- 
nating gold,"  Au2(NH3)202. 

PLATINUM. 
(Use  PtCl4  Solution.) 
1.— H2S    precipitates    brown    PtS2,    insoluble    in    HC1   or   in 


24  Q  UALITA  TIVE  ANAL  YSIS. 

(NH4)2C03.  Soluble  in  yellow  ammonium  sulphide,  and  in 
nitrohydrochloric  acid. 

2. — KC1  precipitates  yellow  crystalline  K2PtCl6,  best  after 
addition  of  alcohol. 

3.— NH4C1  precipitates  yellow  crystalline  (NH4)2PtCl6,  best 
after  addition  of  alcohol. 

For  the  separation  of  members  of  this  group,  see  p.  25. 

GROUP  I. 
Lead,  Pb,  Silver,  Ag,  Mercury  (Mercurous),  Hg2. 

LEAD. 

(Use  Pb(NO3)2  Solution.) 

1. — HC1  and  soluble  chlorides  precipitate  white  crystalline  lead 
chloride,  PbCl2,  soluble  in  hot  water. 

2.— H2SO4  (dil.)  precipitates  white  lead  sulphate,  PbS04, 
slightly  soluble  in  water,  freely  soluble  in  ammoniacal  solutions  of 
ammonium  acetate. 

3. — K2Cr04  precipitates  yellow  lead  chromate,  PbCr04,  soluble 
in  fixed  alkalies. 

4. — NH4OH  precipitates  white  basic  lead  hydroxide. 

5. — H2S  precipitates  black  lead  sulphide,  PbS,  insoluble  in 
alkalies  and  alkaline  sulphides,  but  soluble  in  hot  nitric  acid. 

6. — KI  precipitates  yellow  lead  iodide,  PbI2,  soluble  in  hot 
water. 

7. — Borax  bead  ;  appearance  same  as  with  zinc. 

SILVER. 

(Use  AgNO3,  Solution. ) 

1. — HC1  and  soluble  chlorides  precipitate  white  silver  chloride, 
AgCl,  soluble  in  NH4OH,  insoluble  in  HN03. 

2. — KCN  precipitates  white  AgCN  readily  soluble  in  excess. 

3. — H2S04  produces  no  precipitate. 

4. — K2Cr04  precipitates,  from  neutral  solutions,  reddish-brown 
silver  chromate,  Ag2Cr04. 

5. — H2S  precipitates  black  silver  sulphide,  Ag2S. 

MERCURY  (ous). 

(Use  Hg2(NO3)2  Solution. ) 
1. — HC1  precipitates  white  mercurous  chloride,  Hg2Cl2,  which 


ANALYTICAL  SCHEME  FOE  METALS.  25 

turns  black  on  the  addition  of  NH4OH,  mercurous  ammonium 
chloride,  NH2Hg2Cl  being  formed. 

2. — K2Cr04  precipitates  orange  mercurous  chromate,  Hg2Cr04. 

3. — KI  precipitates  yellowish-green  mercurous  iodide,  Hg2T2. 

4. — H2S  precipitates  black  mercuric  sulphide,  HgS,  mixed  with 
mercury. 

For  mercuric  compounds,  seep.  21.     See,  also,  under  Special  Tests. 

For  the  separation  of  the  members  of  this  group,  see  below. 

ANALYTICAL  SCHEME  FOR  METALS.* 

GEOUP  I. 

To  the  solution,  add  dilute  HC1,  drop  by  drop,  as  long  as  a  pre- 
cipitate is  formed,  f  Filter,  and  wash  the  precipitate  with  cold 
water.  (Reserve  the  filtrate  for  Group  II.)  Perforate  the  filter 
paper,  wash  the  precipitate  into  a  test  tube  and  heat  to  boiling 
with  water.  Filter  rapidly  while  the  liquid  is  still  hot. 


The  Filtrate  contains  PbCl2. 
Test  for  lead  with  H2SO4  or 
with  K2CrO4.  Pb 


The  Residue  contains    AgCl    and    Hg2Cl2. 
Wash  with  hot  water.     Treat  the  residue  on 
the  paper  with  dilute  NH4OH.     If  it  turns 
black,  mercury,  Hg,  is  present. 
Dilute  the  ammoniacal  solution  with  water,  and  acidify  with  HNO3.     A  white 
precipitate  indicates  silver,  Ag. 

GROUP  II. 

Pass  H2S  gas  through  the  slightly  acid  J  filtrate  from  Group  L, 
as  long  as  a  precipitate  is  formed.  Filter  and  thoroughly  wash  the 
precipitate.  (Reserve  the  filtrate  for  Group  III. )  Perforate  the 
filter  paper,  wash  the  precipitate  into  a  test  tube,  add  (NH4)2S, 
warm  gently,  filter,  and  wash. 

A.  The  Filtrate  contains  As,  Sb,  Sn,  Au,  .Pt. 

B.  The  Precipitate  contains  Hg,  Pb,  Bi,  Cu,  Cd. 

A.   Acidify  the  filtrate  with  dilute  HC1.     The  sulphides,  if  pres- 

*  For  elementary  laboratory  practice  the  analysis  may  be  simplified  by  omission 
of  Cd,  Bi,  Sn,  Au,  Pt,  Mn,  Ni,  and  Co.  The  remaining  metals  will  offer  no  dif- 
ficulty. 

f  The  HC1  may  precipitate  antimony  and  bismuth  salts  soluble  in  excess  of 
acid.  It  is  well,  therefore,  to  first  test  a  small  part  of  the  solution,  trying  the 
effect  of  acid  in  excess. 

t  Nitrous,  Nitric,  and  Chloric  acids,  as  well  as  other  oxidizing  agents  should  be 
absent.  If  present  remove  by  repeated  evaporations  with  HC1. 


26  Q  U ALII  A  TIVE  ANAL  YSIS. 

ent,  are  reprecipitated.*  Filter,  and  wash  the  precipitate.  Per- 
forate the  filter  paper  and  wash  the  precipitate  into  a  large  test- 
tube.  Add  some  fragments  of  solid  (NH4)2C03  and  warm  for 
several  minutes.  Filter  and  wash. 


Acidify  the  Filtrate  with  dilute  HC1. 
A  yellow  precipitate  =  As2S3.     As 
Apply  Special   Tests   to   the    original 
solution. 


Dissolve   the  Residue    in   hot   HC1, 
dilute  with  water,  and  pass  H2S  gas. 
An     orange-red     precipitate  =  Sb2S3. 
Sb 

In  this  process,  tin,  gold,  and  platinum,  if  present,  will  be  found  in  the  residue 
with  antimony.  If  it  be  desired  to  detect  and  separate  these  metals,  boil  the 
precipitate  with  strong  HC1,  and  filter.  A  remaining  residue  will  be  gold  or 
platinum.  Dissolve  this  in  nitrohydrochloric  acid  and  test  the  solution  with 
SnCl2  for  gold,  Au,  with  KC1  for  platinum,  Pt.  (See  p.  23.) 

The  solution  obtained  above  with  boiling  HC1  is  then  diluted,  and  boiled  in  a 
dish  with  a  piece  of  platinum  foil  and  a  fragment  of  zinc.  Antimony,  Sb,  will  be 
deposited  as  a  coating  on  the  platinum,  from  which  it  may  be  dissolved  in  HNO3 
and  further  tested.  The  tin,  Sn,  will  separate  as  a  spongy  sediment,  which 
may  then  be  dissolved  in  HC1  and  tested  with  HgCl2.  (See  p.  23. ) 

B.  The  precipitate  containing  Hg,  Pb,  Bi,  Cu,  and  Cd.  Per- 
forate the  filter  paper,  wash  the  precipitate  into  a  beaker,  add 
strong  HN03,  boil  for  several  minutes,  and  filter. 


A  Black  Residue  =  HgS.     Hg 

Transfer  the  residue  to  a  porce- 
lain dish,  dissolve  in  HC1+HNO3. 
Boil  off  the  excess  of  acid,  dilute 
with  a  little  water  and  test  for 
mercury  with  NaOH,  see  p.  21. 


The  Filtrate  contains  Pb,  Bi,  Cu,  Cd. 
Boil  off  the  excess  of  acid,  add  a  little  water, 
and  then,  if  lead  be  present,  a  few  drops  of 
dilute  H2SO4.f  A  precipitate=PbSO4.  Pb 
Filter  and  add  NH4OH  to  the  filtrate. 
A  white  flocculent  precipitate  indicates  bis- 
muth, Bi,  filter  and  apply  tests.  If  the 
NH4OH  in  excess  produces  a  dark  blue  color,  then  copper,  Cu,  is  present.  To 
test  for  cadmium,  Cd,  copper  being  absent,  concentrate  the  ammoniacal  solution 
and  pass  H2S  gas.  A  yellow  precipitate  =•  CdS.  If  copper  be  present,  add  KCN 
until  the  blue  color  is  discharged,  and  then  pass  H2S  gas.  Cadmium  will  be 
precipitated  as  yellow  CdS. 

The  method  to  be  used  for  Group  III.  will  be  decided  by  the 
presence  or  absence  of  phosphoric  acid.  Organic  acids,  e.  g. ,  tar- 
taric  acid,  ckric  acid,  etc.,  should  be  absent  in  any  case,  and,  if 

*  A  fine,  yellowish-white  precipitate  here  may  result  from  decomposition  of  the 
ammonium  sulphide  by  the  acid. 

t  If  lead  was  not  found  in  Group  I. ,  test,  first,  only  a  portion  of  the  solution 
with  the  dilute  sulphuric  acid,  then,  if  lead  be  found,  add  the  acid  to  the  rest  of 
the  solution,  filter,  and  proceed  as  above. 


ANALYTICAL  SCHEME  FOE  METALS. 


27 


present,  should  be  destroyed  by  evaporation  of  the  solution  to  dry- 
ness  and  ignition  of  the  residue.  The  ignited  residue  is  then  dis- 
solved in  water  and  hydrochloric  acid,  and  the  analysis  proceeded 
with. 

To  test  for  phosphoric  acid,  dissolve  a  portion  of  the  precipitate 
obtained  on  addition  of  NH4C1  and  NH4OH  (see  scheme  below) 
in  dilute  HN03,  and  add  two  volumes  of  ammonium  molybdate 
solution.  A  yellow  precipitate  indicates  presence  of  phosphoric 
acid. 

GROUP  III.     (PHOSPHATES  ABSENT.  ) 

Boil  the  filtrate  from  Group  II.  until  all  H2S  is  expelled,  add  a 
few  drops  of  strong  HN03  and  again  heat  to  boiling.*  Add  NH4C1 
and  NH4OH.  If  there  be  a  precipitate,  filter.  (The  filtrate  (A) 
is  to  be  reserved  for  the  ammonium  sulphide  test.)  Wash  the 
precipitate,  then  perforate  the  paper  and  wash  the  precipitate  into 
a  test-tube,  add  NaOH  and  boil  for  several  minutes.  Filter,  and 
wash. 


Test  a  portion  of  the  Precipitate  for 
Chromium,  Cr,  by  tests  4  and  5  (p. 
18).  Dissolve  the  remainder  of  the 
precipitate  in  dilute  HC1  and  test  for 
iron,  Fe,  with  KCNS. 


To  the  Filtrate  add  enough  HC1  to 
render  it  faintly  acid,  and  then  add 
(NH4)2CO3.  A  precipitate  indicates 
aluminum,  Al. 


To  the  filtrate  (A)  (reserved  above)  add  (NH4)2S.f  If  a  pre- 
cipitate be  obtained,  filter,  and  wash.  (Reserve  this  filtrate  for 
Group  IV. )  Treat  the  precipitate  on  the  paper  with  cold  dilute 
HC1.  A  black  residue  J  should  be  tested  for  nickel,  Ni,  and 
cobalt,  Co,  by  the  borax  bead,  see  p.  20. 

The  hydrochloric  acid  solution  is  then  boiled.  Cool,  add  a  large 
excess  of  NaOH  and,  after  shaking  well,  filter. 

*  The  nitric  acid  is  added  and  the  solution  boiled  for  the  purpose  of  oxidizing 
iron  ;  an  excess  of  the  acid,  however,  should  be  avoided,  as  should  also  prolonged 
boiling,  otherwise  manganic  hydroxide  may  be  precipitated  on  the  subsequent 
addition  of  the  ammonium  hydroxide. 

t  In  absence  of  Mn,  Ni,  and  Co,  a  grayish-white  precipitate  obtained  on  addi- 
tion of  (NH4)2S  is  sufficient  indication  of  the  presence  of  Zinc. 

$  This  residue  may  be  dissolved  in  aqua  regia,  the  excess  of  acid  removed  by 
boiling,  the  solution  nearly  neutralized  with  Na.2CO3,  and  KCN  added  until  the 
precipitated  cyanides  are  just  redissolved.  Add  NaOH  and  then  bromine  water 
until  the  solution  is  colored.  A  precipitate  indicates  Nickel,  the  solution  may  be 
tested  for  Cobalt. 


28 


QUALITATIVE  ANALYSIS. 


Test   the   Precipitate  for   manganese, 
Mn,  by  test  3,  p.  19. 


To  the  Filtrate  add  (NH4)2S.     A  pre- 
cipitate indicates  Zinc,  Zn. 


GROUP  III.     (PHOSPHATES  PRESENT.) 

Boil  the  filtrate  from  Group  II.  until  all  H2S  is  expelled,  add  a 
few  drops  of  strong  HN03  and  again  heat  to  boiling.  Add  NH4C1 
and  NH4OH,  and  filter.  (Reserve  the  filtrate  for  Group  IV.) 
To  the  filtrate  add  (NH4)2S  and  filter.  Wash  the  two  precipi- 
tates and  then  digest  them  together  in  a  dish  with  (NH4)2S. 
Filter  and  wash.  Dissolve  the  precipitate  in  hot  dilute  HC1,  with 
addition  of  a  small  crystal  of  KC103.  Drive  off  the  chlorine  by 
heat  and  filter  off  any  separated  sulphur.  Nearly  neutralize  the 
solution  by  adding  dilute  sodium  carbonate,  and  then  add  an 
acetic  acid  solution  of  sodium  acetate.  Warm,  and  filter  immedi- 
ately. 


To  the  Filtrate  add  Fe2Cl6  drop  by 
drop,  as  long  as  a  precipitate  forms. 
Warm  for  some  time,  and  filter.  To 
the  filtrate  add  NH4C1  and  NH4OH, 
and  proceed  with  the  analysis  as  de- 
scribed in  the  last  scheme,  phosphates  being  absent.  Test  for  Cr,  Al,  Ni,  Co, 
Mn,  and  Zn,  and  reserve,  as  described,  the  filtrate  from  the  first  ammonium 
sulphide  precipitation  for  Group  IV. 


The  Precipitate  is  boiled  with  NaOH 
for  several  minutes,  and  tested  for  Fe, 
Cr,  and  Al,  as  described  in  the  last 
scheme,  in  absence  of  phosphates. 


GROUP  IV. 

To  the  filtrate  from  Group  III.,  add  HC1,  boil  and  filter.  To 
the  filtrate  add  NH4OH  and  (NH4)2C03,  warm  and  filter. 
(Test  the  filtrate  for  magnesium,  Mg,  with  Na2HP04.)  Dissolve 
the  precipitate  in  a  little  HC1,  evaporate  the  solution  to  dryness 
and  treat  the  residue  with  absolute  alcohol. 


Residue  =  BaCl2. 
Dissolve  in  water, 
and  test  for  barium, 

Ba. 


Evaporate  the  Solution,  to  expel  the  alcohol,  and  con- 
vert the  chlorides  to  nitrates  by  repeated  evaporations  with 
HNO3.  Evaporate  finally  to  dryness,  and  treat  the  residue 
with  absolute  alcohol. 


.  Dis- 
solve in  water  and  test  for 
strontium,  Sr. 


Solution  contains  Ca(NO3)2. 
Test  for  calcium,  Ca. 


ANALYTICAL  SCHEME  FOR  METALS.  29 

ALTERNATIVE  METHOD.  GROUP  IV. 

To  the  filtrate  from  Group  III.  add  NH4C1,(NH4)2C03  and 
NH4OH.  Warm  the  mixture  for  some  time.  Filter.  (Test  the 
filtrate  for  magnesium,  Mg,  with  Na2HP04.)  Dissolve  the  pre- 
cipitated carbonates  in  dilute  acetic  acid,  and  test  a  portion  of  the 
solution  with  K2Cr207  for  barium.  If  a  precipitate  be  obtained, 
add  the  reagent  to  the  rest  of  the  solution  and  filter. 


Precipitate  =  Barium, 


To  a  portion  of  the  Filtrate  add  a  solution  of  CaSO4. 


If  a  precipitate  be  obtained  (the  precipitate  may  form 
slowly)  strontium,  Sr,  is  present;  add  to  the  rest  of  the 


filtrate  a  strong  solution  of  (NH4)2SO4  boil,  filter  and  test 

the  nitrate  for  calcium,  Ca,  with  (1STH4)4C2O4  and  NH4OH.  If  strontium  is  not 
present,  omit  the  addition  of  (NH4)2SO4,  and  test  the  remainder  of  the  filtrate 
at  once  for  calcium. 


GROUP  V. 

Test  the  original  solution  for  Ammonium,  NH4.  (See  p.  15.) 
For  Potassium,  Sodium,  and  Lithium,  use  the  flame  tests  with 
the  original  solution,  or,  evaporate  the  solution  containing  only 
members  of  this  group,  and  heat  strongly.  Dissolve  the  residue 
in  a  little  water,  add  a  few  drops  of  HC1,  filter  if  necessary,  add 
alcohol  and  an  excess  of  PtCl4.  A  precipitate  — K2PtCl6,  K. 
Add  a  little  water,  filter  and  test  the  filtrate  for  sodium  by  the 
flame  test,  and  with  potassium  pyroantimonate.  A  precipitate  = 
H2Na2Sb207,  Na. 

When  lithium  is  to  be  tested  for,  it  is  preferable  to  precipitate 
the  magnesium  in  Group  IV.  with  (NH4)2HP04,  then  to  filter, 
and  to  the  filtrate  to  add  Na2HP04  and  NaOH.  Finally  concen- 
trate by  boiling — a  precipitate  indicates  lithium,  Li. 

EXAMINATION  OF  A  NEUTRAL  OR  SLIGHTLY  ACID  SOLUTION 
CONTAINING  BUT  ONE  METAL. 

1. — Add  dilute  HC1.  Precipitate  :  Soluble  on  heating  with 
water  =  Pb.  Insoluble  in  water,  add  NH4OH;  it  turns  black  =r 
Hg(ous);  it  dissolves  =  Ag. 

2. — Pass  H2S  through  the  slightly  acid  solution.  Precipitate: 
Soluble  in  (NH4)2S— yellowish  =  As,  Sn(ic);  orange  =  Sb; 
black,  or  brownish-black  =  Sn(ous),  Au,  Pt.  Insoluble  in 
(NH4)2S— yellow  =  0d;  black  =  Cu,  Hg(ic),  Pb,  Bi. 


30  QUALITATIVE  ANALYSIS. 

3. — Add  NH4C1  and  NH4OH  to  original  solution.  Precipitate: 
Reddish-brown  =  Fe(ic);  greenish  =  Or,  (Fe(ous));  white  =  Al. 

If  phosphates  are  present,  add,  to  the  original,  NH4OH,  and  then  HC2H3O2  to  acid 
reaction.  Boil  the  mixture. 

(a)  A  precipitate  forms — filter,  wash  into  a  test-tube,  add  NaOH,  and  boil. 
Reddish  residue^Fe.  Greenish  residue=Cr.  No  residue,  but  a  precipitate  is 
obtained  by  boiling  with  NH4C1  =  Al. 

(6)  No  precipitate  forms — test  with  K2CrO4,  a  ppt.  =  Ba.  Add  dilute  H2SO4, 
a  ppt.  =Sr.  Add  (NH4)2C2O4,  a  ppt.  =Ca.  Cool,  add  excess  of  NH4OH, 
a  ppt.  =  Mg,  or  Mn.  Test  the  precipitate  for  Mn  by  test  3  (p.  19). 

If  organic  acids  are  present,  these  must  be  destroyed  before  testing  under  3. 
Evaporate  the  solution  to  dryness,  ignite  the  residue,  and  redissolve  in  water 
acidulated  with  HC1. 

4. — To  solution  not  precipitated  by  NH4C1  and  NH4OH,  add 
(NH4)2S.  Precipitate:  Flesh-tint  =  Mn  ;  dirty  -white  =  ZnJ 
black  =Ni,  Co  (insoluble  in  cold  dilute  HC1). 

5.— Add  (NH4)2C03,  or,  to  original  solution  add  NH4C1, 
(NH4)2C08  and  NH4OH.  Precipitate  =  Ba,  Sr,  Ca.  Filter, 
dissolve  in  dilute  HC2H302,  and  divide  this  solution  into  2  parts. 

(a)  Add  solution  of  CaSO4.  Precipitate:  Ba  (ppt.  forms  at 
once),  Sr  (ppt.  forms  slowly). 

(£>)  If  a  precipitate  was  obtained  in  a,  add  K2O207.  Precipi- 
tate r=Ba.  No  precipitate  is  formed  with  K2O207  =  Sr. 

(c)  No  precipitate  was  obtained  in  a,  add  (NH4)2C2O4  and 
NH  4  OH.  Precipitate  —  Ca. 

6.— If  (NH4)2C03  gave  no  precipitate,  add  Na2HP04.  Pre- 
cipitate —  Mg. 

7. — No  precipitate  having  been  obtained  by  any  of  the  preced- 
ing reagents,  test  the  original  for  Li,  Na,  and  K,  by  the  flame, 
and  for  NH4,  by  heating  with  a  fixed  alkali.  (See  p.  16.) 

The  metal  having  been  determined,  the  examination  for  the 
combined  acid  radical  may  be  conducted  according  to  paragraphs 
1,  2,  4,  5,  8,  and  9,  under  General  Plan  of  Analysis.  (See  p.  36.) 

TESTS  FOR  THE  COMMON  ACIDS. 
HYDROCHLORIC  ACID,  HC1,  AND  CHLORIDES. 
1. — AgN03  precipitates  curdy  white  silver  chloride,  AgCl,  solu- 
ble in  NH4OH,  insoluble  in  HNO3. 

2. — Hg2(N03)2  precipitates  white  mercurous  chloride,  Hg2Cl2. 
3. — Pb(C2H302)2  precipitates  white  crystalline  lead  chloride, 
PbCl2,  soluble  in  hot  water. 


TESTS  FOE  THE  COMMON  ACIDS.  31 

4. — H2S04  and  Mn02  warmed  with  the  solution,  liberate 
chlorine  gas. 

5.— Warmed  with  H2S04,  chlorides  give  off  colorless  fumes  of 
HC1. 

Chlorates:  1.— Warmed  with  H2SO4  chlorates  give  off  yellowish-green  fumes  of 
C12O4.  2.— AgNO3  gives  no  precipitate.  3.— Heated  on  charcoal,  chlorates 
deflagrate. 

Hypochlorites :  1. — Solutions  bleach  litmus.  2. — With  AgNO3  a  precipitate  of 
AgCl  is  slowly  formed.  3.— Warmed  with  H2SO4,  Cl  gas  is  given  off. 

NITRIC  ACID,  HN03,  AND  NITRATES. 

1. — If  strong  HN03  be  boiled  with  copper  filings,  the  acid  is 
decomposed,  red  fumes  of  N02  are  produced,  and  the  liquid  be- 
comes green. 

2. — Add  an  equal  bulk  of  strong  H2S04.  Cool  the  mixture 
and  float  over  it  a  solution  of  FeS04.  At  the  contact  of  the  two 
liquids  a  brown  ring  will  develop. 

3. — A  small  quantity  of  the  fluid  added  to  a  solution  of  brucia 
in  concentrated  H2S04,  develops  a  fine  red  color.  (Chloric  acid 
gives  the  same  reaction. ) 

4. — Nitrates  and  nitric  acid  are  reduced  by  a  mixture  of  zinc 
and  H2S04,  NH3  being  formed. 

Nitrites:  1. — Warmed  with  H2SO4  red  fumes  are  given  off.  (A  nitrate  so 
treated  yields  nearly  colorless  fumes.)  2. — Nitrous  acid,  and  nitrites  in  presence 
of  sulphuric  acid,  give  a  blue  color  with  KI  and  starch  paste.  3.— Floated  over 
a  solution  of  FeSO4,  a  brown  ring  will  form  at  the  contact. 

SULPHURIC  ACID,  H2S04,  AND  SULPHATES. 

1. — Bad 2  precipitates  white  barium  sulphate,  BaS04,  insoluble 
in  boiling  water  or  in  hydrochloric  acid. 

2.— Pb(C2H302)2  precipitates  white  lead  sulphate,  PbS04, 
soluble  only  in  hot  concentrated  acids. 

Sulphides:  1.— Warmed  with  H2SO4,  if  acted  upon  at  all,  give  off  H2S.  2.— 
Insoluble  sulphides  are  decomposed  by  HNO3  with  separation  of  sulphur. 

Sulphites:  1.— Warmed  with  H2SO4,  yield  H2S  and  SO2.  2.— Sulphites  decom- 
pose AgNO3  with  separation  of  Ag.  Sulphurous  acid  first  reddens,  then  bleaches 
litmus  paper. 

Thiosulphates  (Hyposulphites):  1.— Warmed  with  H2SO4  yield  H2S,  SO2,  and 
sulphur.  2. — AgNO3  is  decomposed  with  final  precipitation  of  Ag.2S. 


32  Q  UALITA  TIVE  ANAL  YSIS. 

BORIC  ACID,  H3BO3,  AND  BORATES. 

1. — Solutions  of  the  crystalline  acid  in  glycerine  burn  with  a 
green  flame. 

2. — Solutions  of  the  acid  turn  litmus  paper  red.  Tumeric  paper 
is  at  first  unchanged,  but  on  drying  becomes  reddish-brown.  A 
drop  of  ammonium  hydroxide  placed  on  the  dried  tumeric  paper 
gives  a  bluish-black  spot. 

Sodium  tetraborate,  Na2B4O7,  "  Borax:"  Burns  with  the  yellow  flame  of  sodium , 
and  has  an  alkaline  reaction  with  litmus  paper.  The  green  boric  acid  flame  can 
be  obtained  by  mixing  the  borax  with  a  few  drops  of  H2SO4  and  a  little  alcohol. 
Upon  ignition  the  alcohol  will  burn  with  a  green  mantle.  A  concentrated  solu- 
tion of  borax  warmed  with  CaCl2  and  a  little  NH4OH,  gives  a  precipitate  of  cal- 
cium borate,  soluble  in  HC2H3O2  and  in  excess  of  water. 

CHROMIC  ACID,  H2Cr04,  AND  CHROMATES. 

1. — H2S  gas,  in  acid  solutions,  produces  a  green  color,  due  to 
formation  of  a  chromic  compound,  and  sulphur  is  precipitated. 

2. — AgN03  precipitates  dark  red  Ag2Cr04,  soluble  in  nitric  acid 
and  in  ammonium  hydroxide. 

3. — Treated  with  an  excess  of  H2SO4  and  shaken  with  an  ether- 
ial  solution  of  H202,  a  fine  blue  color  is  produced. 

4. — Hg2(N03)2  precipitates  dark  red  Hg2CrO4. 

Dichromates  (of  alkali  metals) ,  e.  g.,  K2Cr2O7.  Tests  are  similar  to  those  above. 
Test  3  is  best  performed  as  follows:  To  water  in  a  test  tube  add  a  few  drops  of 
H2O2,  acidify  with  one  or  two  drops  of  HC1,  add  a  little  ether  and  then  one  or 
two  drops  of  the  dichromate.  The  etherial  layer  is  colored  blue. 

HYDROBROMIC  ACID,  HBr,  AND  BROMIDES. 

1. — AgN03  precipitates  yellowish-white  silver  bromide,  AgBr, 
insoluble  in  nitric  acid,  slowly  soluble  in  strong,  insoluble  in  dilute 
ammonium  hydroxide. 

2. — Hg2  (N03 )  2  precipitates  yellow  mercurous  bromide,  Hg2Br2. 

3. — Add  a  little  carbon  disulphide,  CS2,  and  then  a  few  drops 
of  chlorine  water.  Mix  well  by  shaking.  The  CS2  acquires  a 
reddish-yellow  tint.  (With  iodides  by  the  same  test,  the  carbon 
disulphide  is  colored  violet-red. ) 

4. — With  starch  paste  and  chlorine  water  a  yellow  color  is  de- 
veloped. 

5. — Warmed  with  H2S04,  brown  fumes  of  bromine  are  evolved. 


TESTS  FOR  THE  COMMON  ACIDS.  33 

HYDROCYANIC  ACID,  HCN,  AND  CYANIDES. 

1. — Note  the  characteristic  odor. 

2. — AgN03  precipitates  white  silver  cyanide,  AgCN,  soluble  in 
KCN,  soluble  in  NH4OH,  and  in  boiling  HN03,  but  insoluble  in 
cold  dilute  HN03.  To  obtain  the  reaction  with  cyanides,  such  as 
KCN,  add  first  a  little  HN03  to  decompose  the  cyanide  and  then 
add  the  AgN03.  The  precipitation  is  distinguished  from  AgCl  by 
its  solubility  in  boiling  HN03,  and  by  the  odor  of  HCN  developed 
on  warming  with  HC1. 

3. — Add  a  few  drops  of  yellow  ammonium  sulphide  and  evapo- 
rate to  dryness  on  the  water-bath.  To  the  residue  add  a  drop  of 
Fe2Cl6.  A  blood-red  color  is  produced,  or,  if  the  black  sulphide 
of  iron  forms,  dissolve  this  in  a  drop  of  dil.  HC1,  and  the  red  color 
will  then  become  apparent. 

4. — Add  NaOH  and  a  few  drops  of  a  solution  of  FeS04  which 
has  been  previously  exposed  to  the  air,  warm  gently,  and  acidify 
with  HC1.  Prussian  blue  will  be  formed  if  HCN  be  present. 

5. — Add  a  few  drops  of  picric  acid  to  a  solution  of  potassium 
cyanide,  and  warm.  Dark  red  potassium  isopurpurate  is  formed. 

HYDRIODIC  ACID,  HI,  AND  IODIDES. 

1. — AgN03  precipitates  yellow  silver  iodide,  Agl,  insoluble  in 
HN08  or  in  NH4OH. 

2. — Hg2(N03)2  precipitates  green  mercurous  iodide,  Hg2I2. 

3. — HgCl2  precipitates  red  mercuric  iodide,  HgI2. 

4. — Add  a  few  drops  of  "Chlorine  water,"  and  then  a  little 
starch  paste.  A  blue  color  is  developed  which  disappears  when 
the  solution  is  heated,  but  reappears  when  the  solution  is  cooled. 
For  free  iodine  the  same  test  is  used  without  the  addition  of  chlo- 
rine water. 

5. — Warmed  with  H2S04  violet  fumes  of  iodine  are  given  off. 

PERMANGANIC  ACID,  H2Mn208,  AND  PERMANGANATES. 

1. — Heated  in  a  dry  tube  permanganates  decrepitate  with  evolu- 
tion of  oxygen. 

2. — Permanganates  dissolve  in  water  to  a  purple-red  solution. 

3.— Acidulate  the  aqueous  solution  with  H2S04  and  pass  H2S 
gas.  The  solution  is  decolorized  and  sulphur  precipitated. 

Manganates  (salts  of  H2MnO4,  green  in  color),  and  Permanganates  are  decom- 


34  Q  UA  LIT  A  TIVE  ANAL  YSIS. 

posed  by  boiling  with  HC1.    Chlorine  gas  is  given  off  and  a  permanent  manganous 
salt  is  produced.     See  tests  on  p.  19. 

PHOSPHORIC  ACID,  H3P04,  AND  ORTHOPHOSPHATES. 

1. — Neutral  Fe2Cl6  with  NaC2H302  precipitates  yellowish- white 
ferric  phosphate,  Fe2(P04)2.  Free  mineral  acids  should  be  ab- 
sent. For  the  preparation  of  neutral  ferric  chloride,  see  Appendix. 

2. — CaCl2  precipitates,  from  solutions  of  soluble  phosphates, 
white  calcium  hydrogen  phosphate,  CaHP04,  soluble  in  acetic 
acid.  Solutions  of  the  free  acid  are  precipitated  only  after  neutral- 
ization. 

3. — AgN03  precipitates  yellow  silver  phosphate,  Ag3P04,  solu- 
ble in  acetic  acid  and  in  ammonium  hydroxide. 

4. — Acidify  with  nitric  acid  and  add  ammonium  molybdate 
(NH4)2Mo04,  a  yellow  precipitate  of  ammonium  phosphomolyb- 
date,  (NH4)3P04(Mo03)102H20,  is  obtained.  Soluble  in  am- 
monium hydroxide. 

5. — "Magnesia  Mixture"  precipitates  white  magnesium  ammo- 
nium phosphate,  Mg(NH4)P04,  soluble  in  all  acids. 

Phosphites:  1. — Warmed  with  AgNO3  in  presence  of  NH4OH,  metallic  silver 
is  separated.  2. — CaCl2  gives  a  white  precipitate.  3. — Magnesia  mixture  gives  a 
precipitate  from  strong  solutions. 

Hypophosphites :  1. — On  ignition  inflammable  PH3  is  given  off.  2. — AgNOj. 
precipitates  white  silver  hypophosphite,  turning  black  on  exposure.  3. — (NH4)2- 
MoO4  gives  a  blue  precipitate.  4. — CaCl2  gives  no  precipitate. 

Pyrophosphates :  1. — AgNO3  precipitates  white  silver  pyrophosphate.  2. — 
MgSO4  precipitates  magnesium  pyrophosphate,  soluble  in  excess  of  the  reagent, 
3. — (NH4)2MoO4  reacts  very  slowly,  or  not  at  all. 

Metaphosphates :  1. — AgNO3  precipitates  white  silver  metaphosphate.  2. — 
(NH4)2MoO4  causes  no  precipitate.  3. — Albumen  forms  a  white  precipitate. 

ACETIC  ACID,  HC2H302,  AND  ACETATES. 

1. — Note  the  characteristic  odor  of  the  acid. 

2. — Neutral  Fe2Cl6  added  to  solutions  of  neutral  acetates  gives 
a  dark  red  color,  destroyed  by  addition  of  either  HC1,  or  HgCl2, 

3. — Warmed  with  a  few  drops  of  H2S04  and  the  same  of  alco- 
hol, C2H5OH,  the  characteristic  odor  of  ethyl  acetate,  C2H5- 
(C2H302)  is  developed. 

4. — With  acetates  the  odor  of  acetic  acid  is  developed  by  warming 
with  sulphuric  acid. 

CARBONIC  ACID,  H2C03,  AND  CARBONATES. 
1. — Acids,  such  as  HC1,  produce  an  effervescence  of  C02  gas. 


TESTS  FOR  THE  COMMON  ACIDS.  35 

2.—  Ca(OH)2  and  Ba(OH)2  precipitate  white  CaC03,  and 
BaC03,  soluble  in  acids  with  effervescence. 

8. — The  CO  2  given  off  in  effervescence  is  colorless  and  prac- 
tically odorless — it  turns  blue  litmus  paper  red,  but  the  blue  color 
is  restored  on  drying  and  warming.  Passed  into  lime  water  the 
gas  produces  a  white  precipitate  which  redissolves  with  excess  of 
the  gas. 

CITRIC  ACID,  H3C6H507,  AND  CITRATES. 

1. — CaCl2  precipitates  from  boiling  solutions  of  citrates,  white 
calcium  citrate,  Ca3(C6H507)2,  soluble  in  HC2H3O2,  insoluble 
in  NaOH,  soluble  in  cold  NH4C1  but  reprecipitated  by  boiling. 
In  testing  the  free  acid  first  render  faintly  alkaline  with  ammonium 
hydroxide,  then  add  the  CaCl2  and  boil. 

2. — AgNO3  produces  with  normal  alkali  citrates  a  white  floccu- 
lent  precipitate  of  silver  citrate,  Ag3C6H507.  On  long  boiling,  a 
partial  separation  of  silver  occurs.  The  precipitate  dissolved  in 
NH4OH  and  boiled  forms  no  mirror  (unlike  the  tartrate). 

3. — Heated  on  platinum  foil,  citric  acid  fuses,  carbonizes,  and 
gives  off  pungent  fumes. 

OXALIC  ACID,  H2C204,  AND  OXALATES. 

1. — CaCl2  precipitates  white  calcium  oxalate,  CaC204,  soluble 
in  HC1,  insoluble  in  HC2H302. 

2. — AgN03  precipitates  white  silver  oxalate,  Ag2C204,  soluble 
in  hot  concentrated  HN03,  and  in  NH4OH. 

3. — Oxalic  acid  added  to  a  solution  of  K2Mn208  acidulated 
with  dilute  H 2 S04,  and  warmed  gently,  completely  removes  the 
color. 

4.— Oxalates,  unlike  citrates  and  tartrates,  are  not  charred  when 
heated  with  H2S04. 

5. — Heated  on  platinum  foil,  oxalates  turn  gray  but  do  not  car- 
bonize. A  carbonate  is  produced,  soluble  in  acids  with  effer- 
vescence. 

SALICYLIC  ACID,  HC7H503,  AND  SALICYLATES. 

1.— Fe2Cl6  in  neutral  solutions  gives  a  deep  violet  color. 
(Compare  with  test  for  Phenol. ) 

2. —Bromine  water  produces  a  yellowish-white  precipitate. 
(See,  also,  Phenol.) 

3— Add  methyl  alcohol  and  one-fourth  volume  of  H2S04;  on 


36  Q  UALITA  TIVE  ANAL  YSIS. 

warming,  the  odor  of  methyl  salicylate  ("Oil  of  Wintergreen " ) 
is  developed. 

4. — Sodium  salicylate,  added  to  a  solution  of  copper  sulphate, 
changes  the  blue  color  of  the  latter  to  a  bright  green. 

TARTARIC  ACID,  H2C4H406,  AND  TARTRATES. 

1. — CaCl2  precipitates  from  solutions  of  tartrates,  white  calcium 
tartrate,  CaC4H4O6.4H20,  soluble  in  HC2H302.  Soluble  also  in 
NaOH,  from  which  solution  it  is  reprecipitated  on  boiling.  In 
testing  the  free  acid  first  render  faintly  alkaline  with  ammonium 
hydroxide. 

2. — From  solutions  of  normal  tartrates,  AgN03  precipitates 
white  silver  tartrate,  Ag2C4H406,  which  blackens  on  boiling.  If, 
instead  of  boiling  the  mixture,  the  precipitate  be  filtered  off  and 
dissolved  in  a  few  drops  of  dilute  NH4OH,  on  boiling,  a  mirror  of 
silver  forms  on  the  tube.  (The  tube  must  be  absolutely  clean.) 

3. — Heated  on  platinum  foil,  tartaric  acid,  or  tartrates,  fuse, 
carbonize,  and  give  off  the  characteristic  odor  of  burnt  sugar. 

GENERAL  PLAN  OF  ANALYSIS. 

PRELIMINARY   EXAMINATION. 

Should  the  substance  be  in  solution,  evaporate  to  dryness  and 
apply  the  following  preliminary  tests  to  the  residue  : 

1. — Heat  a  portion  of  the  powdered  substance  on  platinum  foil: — It 
darkens  and  chars,  giving  the  odor  of  burnt  sugar.  Tartrates, 
citrates,  sugar,  etc. :  It  darkens  slightly,  leaving  a  residue  of  car- 
bonate =  oxalates.  Proteid  matter,  alkaloids,  etc.,  produce  an 
odor  resembling  that  of  burning  hair. 

2. — To  a  little  of  the  powdered  substance  in  a  test-tube  add  a  few  drops 
of  H^SO^.  Note  results  before  and  after  warming  : — Colored  gas — 
Violet  fumes  —  iodides;  brown  fumes  =  bromides;  yellow-green 
fumes  of  Cl  =  hypochlorites;  yellow  C1204  =  chlorates;  reddish- 
brown  fumes  =  nitrites;  nearly  colorless  but  faintty  reddish-brown 
fumes  =  nitrates.  Colorless  gas — Effervescence  in  the  cold,  no  odor 
=  carbonates;  on  heating,  odor  of  H2S  =  sulphides;  odor  of  S02 
=  sulphites;  odor  of  S02  with  separation  "of  S  —  thiosulphates 
(hyposulphites);  odor  of  HCN  =  cyanides;  odor  of  HC2H302  — 
acetates;  acid  fumes  of  HC1  =  chlorides.  Colorless  gases  are  also 
evolved  from  hydrofluoric  acid,  from  chromic,  citric,  oxalic,  malic, 


TESTS  FOR  THE  COMMON  ACIDS.  37 

and  tartaric  acids,  from  formates  and  ferrocyanides,  and  character- 
istic odors  are  obtained  from  benzoates,  succinates  and  valerianates. 
No  gas — Sulphates,  phosphates,  silicates,  borates,  arsenites,  arsen- 
ates,  tungstates,  molybdates,  iodates,  many  oxides,  etc. 

3. — Heat  some  of  the  powder  gently  in  a  Bunsen  flame,  moisten  with 
HC1  and  heat  again.  The  flame  is  colored  yellow  by  Na;  violet  by 
K;  crimson  by  Sr;  carmine-red  by  Li;  reddish-yellow  by  Ca;  green  by 
Ba,  B2O3,  and  Mo;  emerald-green  by  Cu;  bluish-green  by  some 
phosphates;  bluish  by  As,  Sb,  Pb,  CuCl2  and  CuBr2. 

4. — Heat  a  small  portion  of  the  powdered  substance  in  a  dry  ignition 
tube.  It  blackens : — Organic  compounds  and  certain  salts  of  copper 
and  cobalt.  It  changes  color: — Yellow  when  hot,  white  when 
cold  =  ZnO  and  many  zinc  salts;  yellow  both  hot  and  cold  =  lead 
oxide;  red-brown  when  hot,  pale  yellow  when  cold  =  Bi203  and 
certain  bismuth  salts;  red  to  black  when  hot,  reddish-brown  when 
cold  =  Fe203  and  salts  of  iron;  brown  both  hot  and  cold  =  cad- 
mium salts;  brown  when  hot,  yellow  when  cold  =  Sn02.  It 
fuses: — Many  alkaline  and  other  salts,  also  tartaric  and  citric  acids 
before  charring.  It  sublimes  : — The  sublimate  is — gray  and  easily 
rubbed  into  globules  =  Hg;  white  crystalline,  the  substance  first 
melting  =  HgCl2;  sublimate  yellow  when  hot,  white  when  cold  — 
Hg2Cl2;  black,  but  red  on  rubbing  =  HgS;  steel-gray,  odor  of 
garlic  =  As;  white  octahedral  crystals  =  As203 ;  nearly  black  when 
hot,  reddish-yellow  when  cold  =  As2S3;  substance  fuses  yellow, 
white  amorphous  sublimate  =  Sb2S8;  reddish-yellow  stain=Fe2- 
C16;  reddish-brown  drops,  yellow  when  cold  =  S;  heavy  white 
vapor  and  crystalline  sublimate rr:H2Cr04;  violet  vapor,  bluish- 
black  sublimate  =  1.  A  gas  or  vapor  is  given  off: — The  gas  is  0  = 
nitrates,  chlorates,  iodates,  peroxides;  H2S  =  hydrated  sulphides, 
some  sulphites;  SO 2  —  sulphites,  hyposulphites,  and  a  few  sul- 
phates; NH3  =  ammonium  compounds;  Oxides  of  N  =  nitrates, 
nitrites;  H20  =  hydrates,  and  crystalline  salts.  Fumes  are  also 
given  off  from  chromic  acid  and  iodine,  from  cyanides,  from 
bromine,  and  from  acetates. 

5. — Heated  on  charcoal: — The  substance  deflagrates  =  nitrates, 
chlorates,  iodates,  permanganates,  etc.  An  incrustation  is  formed 
on  the  charcoal;  Yellow  when  hot,  white  when  cold^Sn,  Zn; 
yellow  both  hot  and  cold  =  Pb,  Bi;  reddish-brown  =  Cd;  white  = 
As,  Sb. 


38  Q  UALITA  TIVE  ANAL  YSIS. 

PREPARATION  OF  THE  SOLUTION  FOR  ANALYSIS. 

6. — If  the  substance  be  a  metal,  dissolve  in  HN03  (Au  and  Pt 
are  insoluble  in  HN03,  soluble  in  nitro-hydrochloric  acid.  Sb  and 
Sn  may  separate  as  white  oxides,  filter,  wash,  and  dissolve  in 
HC1. )  Evaporate  the  solution  to  dryness  and  dissolve  the  residue 
in  water  containing  a  little  HN03. 

If  the  substance  be  a  solid,  but  not  a  metal,  reduce  it  to  a 
powder.  To  a  portion  add  water  and  boil  :  (a)  If  all,  or  part, 
dissolves,  examine  the  solution  obtained,  for  bases.  (6)  To  the 
portion,  if  any,  insoluble  in  water,  add  HC1  and  boil,  (c)  Dis- 
solve any  remaining  residue  in  HN03.  or  in  nitro-hydrochloric 
acid.  When  strong  acids  are  required  for  the  solution,  it  is  best 
to  evaporate  the  solution  to  dryness  and  to  redissolve  in  acidified 
water  before  proceeding  with  the  analysis,  (d)  A  residue  insol- 
uble in  acids  may  be — silica,  silicates:  sulphate  of  barium,  stron- 
tium, or  lead;  halogen  salts  of  silver;  oxides  of  iron,  manganese, 
aluminum,  chromium,  and  tin,  after  high  heating;  carbon,  or  sul- 
phur. Carbon  may  be  removed  by  ignition,  sulphur,  by  solution 
in  CS2.  The  residue  may  be  fus^d  with  NaC03,  or  with  a  mix- 
ture of  Na2C03  and  NaN03,  and  the  fused  mass  dissolved  in  acid- 
ified water.  Certain  of  these  insoluble  substances  may  be  sug- 
gested by  the  results  of  the  preliminary  examination,  in  which 
case  special  tests  may  be  used  for  their  identification. 

EXAMINATION  FOR  METALS  AND  ACIDS. 

7. — For  Metals :  Examine  for  metals  according  to  the  Analytical 
Scheme,  page  25.  If  organic  substances  be  present,  ignite  the 
residue,  after  evaporation  of  the  solution,  and  dissolve  in  water 
acidulated  with  HC1.  Group  I.  metals  will  remain  undissolved  in 
the  hydrochloric  acid,  and  may  be  tested  for  in  the  residue. 

8. — For  Acids:  Note  that  if  the  substance  be  soluble  in  water, 
acids  forming  insoluble  salts  with  the  metals  found  can  not  be 
present.  Refer  to  the  table  of  solubilities  in  the  Appendix  and 
use  the  information  so  obtained  in  the  selection  of  the  tests  to 
follow.  The  preliminary  examination,  moreover,  may  have  indi- 
cated the  possible  presence  of  certain  acids,  and  these  may  now  be 
tested  for  directly. 

If  compounds  of  the  alkalies  only  are  present,  proceed  at  once 
with  the  tests  given  below  (A  to  G). 

If  metals  other  than  alkalies  are  present,  add  Na2C03  to  alka- 


TESTS  FOR  THE  COMMON  ACIDS.  39 

line  reaction,  boil,  and  filter.  Divide  the  filtrate  into  two  unequal 
parts.  To  the  larger  part  add  HC1  until  slightly  acid,  boil  thor- 
oughly to  remove  all  C02,  and  test  according  to  A,  B,  C,  E,  F and 
G.  To  the  smaller  portion  add  HN03  to  acid  reaction,  boil  to 
expel  all  C02,  and  test  according  to  D. 

Arsenic  or  antimony,  if  present,  may  be  removed  by  passing 
H2S  through  the  solution  (slightly  acidified  if  necessary).  Filter, 
to  the  filtrate  add  Na2C03,  and  proceed  as  described  above. 
Copper,  if  present,  is  more  completely  precipitated  by  addition  of 
a  little  NaOH  along  with  the  Na2C03. 

(A*)  Acidify  a  portion  of  the  solution  with  HC1.  An  effer- 
vescence =  Carbonates.  (If  Na2C03  has  to  be  added,  to  remove 
the  bases,  test  the  original  solid  or  solution  for  the  carbonates. ) 
Divide  into  three  parts,  (a)  Add  BaCl2:  a  precipitate  insoluble 
in  hot  nitric  acid  =  Sulphates.  (6)  Add  Fe2Cl6:  a  dark-blue  pre- 
cipitate  =  Ferrocyanides ;  a  blood-red  color  destroyed  by  addition 
of  HgCl2  =  Sulphocya.nates ;  a  blood-red  color  not  destroyed  by 
addition  of  HgCl2  =  Meconates.  (c)  Add  FeS04:  a  dark-blue  pre- 
cipitate =  Ferricyanides. 

(B)  Acidify  a  portion  of  the  solution  with  HC2H302.     Divide 
into  two  parts,      (aa)  Add  Cad2:  a  white  precipitate,  soluble  in 
HC1=  Oxcdates.    (bb)  Add  NaC2H302  solution  and  a  little  neutral 
Fe2Cl6:  a   precipitate  —  Phosphates.     Note   that   presence   of  free 
mineral  acid  will  prevent  this  reaction.     Phosphates  may  be  tested 
for,  also,  by  the  molybdate  test,  see  page  34. 

(C)  Add  to  the  solution  enough  dilute  NH4OH  to  give  a  faint 
alkaline  reaction,  then  add  CaCl2:  a  precipitate  soluble  in  NaOH, 
but  reprecipitated  by  boiling  =  Tartrates.     If  no  precipitate  form 
after  shaking  and  standing,  boil  the  mixture;  a  precipitate  now 
forming  =  Citrates. 

If  sulphates  be  present  test  for  oxalates,  tartrates,  etc.,  as  follows,  using  the 
filtrate  from  the  precipitate  obtained  by  adding  BaCl2  in  (A).  Bender  the 
filtrate  faintly  alkaline  with  NH4OH  and  add  CaCl2.  Let  stand  for  several 
minutes,  filter,  and  reserve  the  precipitate.  Boil  the  filtrate;  a  precipitate  sol- 
uble in  NH4C1  and  reprecipitated  by  boiling=  Citrates. 

Wash  the  precipitate  reserved  above  and  pour  upon  the  paper  acetic  acid;  an 
insoluble  residue^  Oxalates.  The  acetic  acid  solution  is  now  tested  for  Tartrates, 
and  for  Phosphates,  by  the  tests  already  given. 

(D)  Acidify  a  portion   of  the  solution  with   HN03    and   add 
AgN03.     If   a   precipitate  form,   warm  the  mixture,   filter,  and 
wash.     Treat  the  precipitate  on  the  paper  with  dilute  NH4OH 


40  Q  UALITA  TIVE  ANAL  YSIS. 

(1-20).  To  the  solution  obtained  add  HN03;  a  precipitate  = 
chlorides,  cyanides  (oxalates).  Boil  with  strong  HN03.  If  the 
precipitate  be  due  to  Chlorides  it  will  remain  undissolved,  if  due  to 
Cyanides  (or  oxalates)  it  will  dissolve.  In  presence  of  chlorides, 
the  cyanides  may  be  recognized  by  their  characteristic  odor,  devel- 
oped by  decomposition  of  the  precipitate  with  hot  HC1. 

A  residue  left  after  the  treatment  of  the  first  precipitate  with 
dilute  NH4OH  may  be  bromides  or  iodides.  Bromides  are  soluble 
in  strong  NH4OH;  Iodides  are  insoluble  in  strong  NH4OH.  To 
further  identify  these  substances,  add  to  the  original  solution  a 
little  starch  paste  and  a  few  drops  of  chlorine  water,  a  blue  color 
=  Iodides.  Continue  the  addition  of  the  chlorine  water  until  the 
blue  color  is  destroyed,  shake  with  chloroform;  the  chloroform  is 
colored  brownish-yellow  =  Bromides. 

(J£)  Apply  the  FeS04  test  for  Nitrates,  see  page  31. 

(F)  To  the  solution,  carefully  neutralized  if  necessary,  add 
neutral  Fe2Cl6 :  A  red  color  easily  destroyed  by  addition  of  HC1  = 
Acetates.  (Test  for  acetates,  also,  by  test  3,  page  34. )  A  red  color 
not  destroyed  by  addition  of  HC1  =  Pyrogallates  (Sulphocyanates, 
Meconates).  Pyrogallates  turn  black  on  addition  of  NaOH  and 
exposure  to  the  air. 

A  blue-black  color  on  addition  of  the  neutral  Fe2Cl6  may  be 
due  to  Gallates  or  to  Tannates ;  the  latter  precipitate  gelatin  (best 
after  addition  of  a  little  alum),  the  former  do  not  precipitate 
gelatin. 

A  violet  coloration  may  be  due  to  Phenol  or  to  phenol  deriva- 
tives, SalicylateSj  etc.  A  pinkish  precipitate  may  be  due  to  Ben- 
zoates  or  to  Succinates.  Dissolve  the  precipitate  in  dilute  NH4OH, 
concentrate  the  solution  and  add  HC1,  benzoic  acid  will  separate 
in  silky  needles. 

(  6r)  Test  for  Borates,  see  page  32. 

9. — Acids  other  than  those  mentioned  in  the  last  paragraph 
may  be  indicated  in  the  preliminary  examination,  and  may  be 
identified  by  special  tests.  Chromates,  Manganates  and  Perman- 
ganates will  be  suggested  by  the  color  of  their  solutions,  by  certain 
of  the  preliminary  tests  and  by  the  determination  of  their  metals 
in  the  analysis  for  bases.  They  may  be  identified  by  the  tests 
given  on  pages  32  and  33. 

Hydroxides  and  Oxides  will  be  suggested  by  negative  results  wdth 
the  foregoing  tests.  The  hydroxides  and  oxides  of  the  metals  of 


SPECIAL  TESTS.  41 

Groups  IV.  and  V.  are  nearly  all  easily  soluble  in  water;  other 
hydroxides  and  oxides  are  insoluble  in  water. 

SPECIAL  TESTS. 
ARSENIC. 

1. — Place  a  small  particle  of  arsenious  oxide  in  a  reduction 
tube,  and  above  it  in  the  tube  a  splinter  of  charcoal.  Heat  first 
the  coal,  then  the  arsenic;  a  mirror  of  metallic  arsenic  will  form 
on  the  glass  above  the  coal.  Remove  the  coal  and  heat  the  mirror; 
a  crystalline  sublimate  of  arsenious  oxide  will  be  obtained  in  the 
cool  portion  of  the  tube. 

2. — Marsh's  Test. — The  apparatus  consists  of  a  flask  provided 
with  a  safety  tube,  for  the  introduction  of  the  solution,  and  a  de- 
livery tube  for  the  exit  of  the  gases  evolved.  The  latter  pass  into 
a  wide  tube  containing  calcium  chloride,  and  thence  into  a  long 
tube  of  smaller  bore,  contracted  at  intervals  and  drawn  to  a  fine 
point  at  the  end.  Zinc,  water,  and  sulphuric  acid  are  brought 
together  in  the  flask,  and  the  solution  under  analysis  added. 
Hydrogen  gas,  and,  in  presence  of  arsenical  compounds,  arsenetted 
hydrogen  gas  are  produced.  The  inflammable  gas  issuing  at  the 
end  of  the  tube,  in  presence  of  arsenetted  hydrogen  burns  with  a 
bluish-white  flame,  and  gives  off  white  fumes  which  may  be  col- 
lected and  examined  microscopically  for  crystals  of  As2O3.  If  a 
cold  surface,  such  as  a  piece  of  porcelain,  be  held  in  the  flame, 
metallic  arsenic  is  deposited  in  a  brilliant  steel-gray  to  brown 
mirror.  By  heating  the  long  tube  near  one  of  its  contractions  a 
fine  mirror  of  arsenic  is  deposited  on  the  glass  just  in  advance  of 
the  flame.  If  the  gas  be  passed  into  a  solution  of  silver  nitrate, 
metallic  silver  is  deposited  in  black  flakes.  After  filtering,  the 
clear  solution  may  be  examined  for  As2O3.  Antimony  gives 
somewhat  similar  tests,  but  may  easily  be  distinguished.  (See 
under  Antimony. )  Organic  matter  must  be  absent  and  the  re- 
agents used  must  be  absolutely  pure. 

2. — Fleitmann's  Test. — This  is  similar  to  Marsh's  Test,  depend- 
ing upon  the  production  of  arsenetted  hydrogen  by  the  action  of 
nascent  hydrogen  on  a  reducible  arsenical  compound.  Potassium 
hydroxide  or  sodium  hydroxide  is  placed  with  zinc  in  a  test-tube 
and  the  solution  to  be  tested  added.  A  paper  moistened  with 
silver  nitrate  is  held  at  the  mouth  of  the  tube;  the  mixture  is 
boiled,  and  in  the  presence  of  arsenic  the  paper  is  blackened  by 


42  Q  UALITA  TIVE  ANAL  YSIS. 

the  reduction  of  the  silver  nitrate  to  metallic  silver.  This  test  is 
not  given  by  antimony. 

3. — Reinsch's  Test.— The  solution  to  be  tested  is  acidulated  with 
hydrochloric  acid,  a  strip  of  pure  bright  copper  foil  is  introduced 
and  the  mixture  boiled.  In  the  presence  of  arsenical  compounds, 
a  steel-gray  deposit  of  arsenic  forms  upon  the  copper.  Antimony, 
mercury,  and  even  organic  matter,  may  produce  a  similar  appear- 
ance, but  the  arsenic  may  be  identified  as  follows:  The  copper  slip 
is  removed,  washed  carefully,  and  dried  between  folds  of  filter 
paper.  A  strip  is  then  cut,  rolled  into  a  small  coil,  introduced 
into  clean  reduction- tube  and  heated.  The  arsenic  volatilizes,  and 
collects  in  the  cooler  portions  of  the  tube  in  white  octahedral 
crystals  of  As203.  Organic  matter  is  burned  away  without  the 
formation  of  a  sublimate.  (For  Antimony  and  Mercury,  see 
below. ) 

4. — Heated  with  charcoal,  arsenous  and  arsenic  oxides  are  vola- 
tilized, giving  off  the  characteristic  odor  of  garlic. 

(Other  tests  for  arsSnic,  see  p.  20.) 

ANTIMONY. 

1. — Marsh's  Test. — This  test  is  performed  as  described  under 
arsenic,  similar  mirrors  of  metallic  nature  being  formed.  Anti- 
mony is  distinguished  from  arsenic  as  follows:  The  deposit  ob- 
tained by  holding  a  cold  surface  in  the  flame  is  insoluble  in  solu- 
tions of  sodium  or  calcium  hypochlorite  (arsenic  spots — soluble). 
If  the  spot  be  dissolved  in  a  drop  of  nitric  acid,  the  solution 
evaporated  to  dryness,  and  the  residue  moistened  with  a  drop  of 
silver  nitrate,  no  color  is  developed  (arsenic — a  brick-red  color). 
The  spot  dissolved  in  ammonium  sulphide  and  evaporated  to  dry- 
ness,  yields  an  orange- red  residue  (arsenic — bright  yellow).  The 
antimony  mirror  obtained  by  heating  the  tube  is  formed  imme- 
diately above  the  flame  (with  arsenic,  in  advance  of  the  flame), 
is  darker  than  the  arsenical  mirror  and  less  volatile.  Antimonet- 
ted  hydrogen  does  not  precipitate  metallic  silver  from  solutions  of 
silver  nitrate,  but  does  precipitate  black  silver  antimonide. 

2. — Reinsch's  Test. — Performed  as  indicated  under  arsenic.  The 
antimony  coating  is  distinguished  from  arsenic  by  the  fact  that 
when  heated  in  the  reduction-tube,  the  sublimate  produced  is 
either  amorphous  or  composed  of  fine  acicular  crystals. 

(Other  tests  for  antimony,  see  page  21.) 


SPECIAL  TESTS.  43 

MERCURY. 

1. — The  solution  to  be  tested  is  acidulated  with  hydrochloric 
acid,  and  a  strip  of  pure  bright  copper  is  introduced.  A  deposit 
of  metallic  mercury  (silvery  white  by  gentle  friction)  is  formed  in 
the  cold.  (Compare  with  Reinsch's  Test  for  Arsenic.)  If  the 
copper  be  dried  and  heated  as  in  Reinsch's  Test,  a  sublimate  of 
metallic  globules  of  mercury  is  formed. 

To  test  for  corrosive  sublimate  in  calomel,  treat  the  calomel  with 
hot  water,  filter,  and  test  the  filtrate  for  mercury.  Calomel  is  in- 
soluble in  water,  corrosive  sublimate  is  soluble.  Calomel  is  turned 
black  by  addition  of  ammonium  hydroxide,  corrosive  sublimate  is 
not.  (Other  tests  for  mercury,  see  pages  21  and  24.) 

ALCOHOL,  C2H5OH. 

1. — To  a  dilute  solution  of  potassium  dichromate  add  a  few 
drops  of  strong  sulphuric  acid,  and  then  a  little  alcohol,  or  the 
solution  to  be  tested.  Warm  the  mixture:  it  turns  green,  and  the 
characteristic  odor  of  aldehyde,  CH3COH,  is  produced. 

2. — To  the  liquid  to  be  tested  add  a  few  drops  of  dilute  sodium 
hydroxide,  warm  to  about  50°  C.,  then  add  a  solution  of  iodine  in 
potassium  iodide  until  the  liquid  is  faintly  colored.     A  precipitate 
of  iodoform  will  be  produced.     Note  the  characteristic  odor. 
C2H5OH  +  6KOH  +  I8  =  CHI3  +  CH02K  +  5KI  +  5H20. 

An  excess  of  alcohol  holds  the  iodoform  in  solution. 

3. — Add  a  little  sulphuric  acid  and  some  strong  solution  of 
sodium  acetate.  The  characteristic  odor  of  acetic  ether,  (ethyl 
acetate)  C2H5(C2H302),  is  developed  on  warming. 

4. — To  test  for  "fusel  oil"  in  alcohol,  dilute  the  latter  to  a 
strength  of  about  12  per  cent.,  shake  with  chloroform,  separate 
and  evaporate  the  chloroform  extract.  On  warming  the  residue 
with  potassium  acetate  and  a  few  drops  of  sulphuric  acid,  the 
characteristic  odor  of  amyl  acetate  will  be  developed. 

Tests  for  Purity. — It  should  not  affect  the  color  of  litmus  paper. 
Fifty  c.c.  on  evaporation  should  leave  no  color  and  no  weighable 
residue,  and  should  give  no  foreign  odor.  Mixed  with  one-half  its 
volume  of  potassium  hydroxide  the  liquid  should  not  at  once  be- 
come dark  colored.  Tested  with  one-twentieth  its  volume  of  silver 
nitrate,  the  mixture  should  not  become  more  than  faintly  opales- 
cent, and,  011  exposure  to  diffused  daylight  for  six  hours,  should 
not  acquire  more  than  a  faint  brownish  tint. 


44  Q  UALITA  TIVE  ANAL  YSIS. 

CHLORAL  HYDRATE  (CHLORAL),  CC13COH.H2O. 

1. — Add  a  solution  of  sodium  hydroxide  and  warm;  the  chloral 
is  decomposed  with  the  formation  of  chloroform  and  sodium  for- 
mate. Note  the  odor. 

2. — Add  the  chloral  to  dilute  ammonio-silver  nitrate  and  warm 
gently ;  a  silver  mirror  is  formed  on  the  tube.  This  reaction  is 
characteristic  of  all  aldehydes. 

3. — Add  acetic  acid  and  then  ammonium  sulphide  to  a  dilute 
aqueous  solution  of  chloral.  A  brownish-red  color,  or  precipitate, 
and  a  penetrating  odor  will  develop. 

4. — Chloral  may  be  extracted  from  an  aqueous  solution  by 
agitation  with  ether.  Triturated  with  camphor,  the  whole  lique- 
fies. Note,  also,  that  chloral  will  respond  to  the  first  test  given 
below  for  chloroform. 

CHLOROFORM,  CHC13. 

1. — To  some  alcoholic  potassium  hydroxide  in  a  test  tube  add  a 
few  drops  of  aniline,  and  one  or  two  drops  of  chloroform,  or  of 
the  solution  to  be  tested.  Warm  gently;  the  disagreeable  odor  of 
phenyl-isocyanide,  C6H5NC,  is  produced. 

2. — A  strip  of  paper  moistened  with  chloroform,  when  ignited, 
burns  with  a  greenish  flame,  and  gives  off  fumes  of  hydrochloric 
acid. 

3. — Heat  some  of  the  liquid  with  Fehling's  solution.  Red 
cuprous  oxide  is  precipitated  as  in  the  test  for  dextrose  (q.  v. ). 

4. — Evaporate  an  alcoholic  solution  of  phenol  and  potassium 
hydroxide,  and  to  the  hot  residue  add  a  few  drops  of  chloroform, 
or  of  the  liquid  to  be  tested.  A  reddish-purple  color  is  developed. 

Tests  for  purity. — Should  yield  no  foreign  odor  on  evaporation. 
Shaken  with  water  the  latter  on  evaporation  should  be  neutral  to 
litmus  and  should  not  be  affected  by  addition  of  silver  nitrate  or 
of  potassium  iodide.  With  barium  hydroxide  in  a  corked  tube, 
on  standing  for  several  hours  in  a  dark  place,  there  should  be  no 
film  at  the  contact  of  the  two  liquids.  Shaken  with  one-tenth  part 
of  strong  sulphuric  acid,  and  allowed  to  stand,  the  chloroform 
should  remain  colorless  and  the  acid  should  not  be  more  than 
faintly  colored. 

ETHYL  ETHER  (C2H5)20. 

Ether  is  best  recognized  by  its  odor,  volatility,  and  inflamma- 
bility. It  burns  with  a  luminous  flame. 


SPECIAL  TESTS.  45 

Tests  for  purity. — Ether  should  boil  at  about  the  temperature  of 
the  body.  Should  not  affect  the  color  of  litmus  paper;  should 
leave  no  residue  and  should  give  no  foreign  odor  on  evaporation. 
Twenty  c.c.  of  ether  mixed  with  20  c.c.  of  water  previously  satu- 
rated with  ether,  should  show  not  less  than  19.5  c.c.  of  ether  after 
separation  of  the  two  liquids.  Shaken  with  one-tenth  part  of 
potassium  hydroxide  solution,  there  should  be  no  color  in  either 
liquid  after  one  hour. 

FORMALDEHYDE,  HCOH. 

Produced  by  the  oxidation  of  methyl  alcohol,  is  a  gas,  soluble 
in  water  and  in  alcohol.  (Formalin  is  a  40  per  cent,  aqueous 
solution. ) 

Phenylhydrazin  test.  To  1  c.c.  of  the  liquid  add  2  drops  of  a 
solution  consisting  of  1  gramme  of  phenylhydrazin  hydrochloride 
with  1.5  grammes  of  sodium  acetate  in  10  c.c.  of  water,  then  add 
2  drops  of  sulphuric  acid.  A  green  color  is  developed  (in  dilute 
solutions  slowly,  and  best  after  warming). 

For  other  tests,  see  under  Milk  Analysis. 

GLYCEROL  (GLYCERIN),  C3H5(OH)3. 

1. — Add  sodium  hydroxide  to  a  slightly  alkaline  reaction,  and 
heat,  in  a  non-luminous  flame,  a  borax  bead  moistened  with  this 
solution.  Boric  acid  is  produced  and  the  flame  is  colored  green. 

2. — Warm  the  solution  with  sulphuric  acid.  The  characteristic 
odor  of  acrolein,  C3H4O,  is  produced. 

3. — To  detect  glycerol  in  a  saccharine  liquid,  mix  the  latter  with 
Ca(OH)2  and  sand,  and  evaporate  on  a  water  bath.  Extract  the 
nearly  dry  residue  with  alcoholic  ether  and  evaporate  the  extract. 
Test  the  residue  with  the  borax  bead,  as  in  test  1. 

For  medicinal  use,  the  aqueous  solution  of  glycerol  should  be 
neutral  to  litmus  paper;  no  brown  color  should  develop  when  it  is 
treated  with  sulphuric  acid,  and  no  red  precipitate  should  be  ob- 
tained on  heating  with  Fehling's  solution. 

HYDROGEN  DIOXIDE,  H202. 

A  colorless,  odorless  liquid,  with  slight  acid  taste  and  reaction, 
the  acidity  being  due  to  acid  used  in  the  manufacture. 

To  10  c.c.  of  water  in  a  test  tube  add  1  drop  of  potassium 
chromate,  10  drops  of  dilute  sulphuric  acid,  a  few  c.c.  of  ether, 
and  then  a  few  drops  of  the  hydrogen  dioxide,  or  of  the  solution 


46  QUA  LIT  A  TIVE  ANAL  Y81S. 

to  be  tested.     The  presence  of  the  dioxide  is  indicated  by  the  pro- 
duction of  a  blue  color. 

PHENOL  (CARBOLIC  ACID),  C6H5OH. 

1. — Note  the  characteristic  odor,  and  the  greasy  stain  upon 
paper. 

2. — Heated  with  excess  of  strong  nitric  acid  the  solution  turns 
yellow,  trinitrophenol  (picric  acid),  C6H2(N02)3OH,  being 
formed. 

3. — A  few  drops  of  ferric  chloride  impart  a  violet-blue  color  to 
the  solution.  Alcohol  should  be  absent. 

4. — Add  a  few  drops  of  the  solution  to  a  little  hydrochloric  acid 
in  a  test  tube,  then  add  one  drop  of  nitric  acid  and  warm  gently. 
A  purple-red  color  is  developed. 

5. — Mix  the  solution  with  one-quarter  volume  of  ammonia,  add 
a  few  drops  of  sodium  hypochlorite  solution,  and  warm.  A  bluish- 
green  color  is  developed,  turning  to  a  red  on  addition  of  hydro- 
chloric acid. 

6. — The  addition  of  bromine  water  produces  a  precipitate  of 
tribrom-phenol,  C6H2Br3OH,  soluble  in  excess  of  phenol. 

7. — Add  a  few  drops  of  Millon's  reagent  (see  Appendix)  and 
heat  to  boiling;  an  intense  dark  red  color  is  obtained. 

TESTS  FOR  THE  COMMON  ALKALOIDS.* 

The  alkaloids  may  be  described  as  organic,  nitrogenous  sub- 
stances, basic  in  character,  capable  of  combining  directly  with 
acids  to  form  salts.  They  are  commonly  divided  into  two  groups: 
(1)  Liquid  or  Volatile  Alkaloids,  containing  carbon,  hydrogen 
and  nitrogen.  Nicotine,  Sparteine,  and  Coniine.  (2)  Fixed  or 
Non-Volatile  Alkaloids,  containing  carbon,  hydrogen,  nitrogen 
and  oxygen.  Morphine,  Quinine,  Atropine,  Strychnine,  etc. 

General  Properties. — Most  alkaloids  are  insoluble,  or  very  slightly 
soluble  in  water;  more  soluble  in  alcohol,  chloroform  and  benzene. 
The  salts  of  the  alkaloids,  on  the  other  hand,  are  generally  soluble 
in  water  and  in  alcohol,  and  less  soluble  in  chloroform  and  ben- 

*  Unless  otherwise  instructed,  the  tests  for  alkaloids  should  be  made  upon 
watch  glasses,  a  minute  crystal  of  the  alkaloid  being  dissolved  in  as  little  of  the 
solvent  as  possible,  and  the  reagent  added  drop  by  drop.  A  soluble  salt  of  the 
alkaloid  may  be  used,  or  a  solution  may  be  made  in  water  slightly  acidulated  with 
sulphuric  acid. 


TESTS  FOE  THE  COMMON  ALKALOIDS.  47 

zene.  In  appearance,  they  are  generally  white,  with  strong  taste, 
and  characteristic  physiological  action.  The  hydroxides  of  the 
alkalies  and  alkaline  earths  precipitate  alkaloids  from  aqueous 
solutions  of  their  salts.  Alkali  carbonates  precipitate  most  of  the 
alkaloids.  Among  other  precipitants  applicable  in  general  to  the 
whole  class,  we  have  tannic  acid,  picric  acid,  phospho-molybdic 
acid,  solution  of  iodine  in  potassium  iodide,  mercuric  potassium 
iodide  (Mayer's  solution),  and  the  chlorides  of  platinum  and  gold. 

VOLATILE  ALKALOIDS. 

These  are  volatile  liquids,  colorless  when  pure  and  first  separ- 
ated, but  turning  brown  on  exposure  to  the  air.  They  are  charac- 
terized by  disagreeable  penetrating  odors. 

Nicotine,  C10H14N2.  1. — Acrid  odor  and  taste  (a  rapidly  fatal 
poison),  soluble  in  ether,  chloroform,  turpentine,  water  and  alcohol. 

2. — Picric  acid,  platinic  chloride,  and  mercuric  chloride  produce 
precipitates  generally  amorphous  at  first,  changing  to  crystalline. 
The  alkalies,  potassium  iodide,  and  potassium  chromate,  give  no 
precipitates. 

3. — If  a  drop  be  placed  upon  a  watch-glass  and  covered  with  a 
second  watch-glass  carrying  a  drop  of  hydrochloric  acid,  white 
fumes  are  produced. 

4. — An  etherial  solution  of  iodine  added  to  an  etherial  solution 
of  the  alkaloid  separates  a  brownish  oil,  which  gradually  becomes 
crystalline. 

5. — With  the  pure  alkaloid,  strong  hydrochloric  acid  develops  a 
violet  color;  nitric  acid,  an  orange-red  color;  sulphuric  acid  shows 
no  change. 

Coniine,  C8Hl  7N.  1.— Resembles  nicotine,  less  soluble  in  water, 
freely  soluble  in  ether  and  chloroform. 

2. — Picric  acid  and  mercuric  chloride  give  precipitates.  The 
alkalies,  potassium  iodide,  potassium  chromate,  and  platinic  chlor- 
ide, give  no  precipitates. 

3. — If  a  drop  be  placed  upon  a  watch-glass  and  covered  with  a 
second  watch-glass  carrying  a  drop  of  hydrochloric  acid,  white 
fumes  are  produced  and  the  drop  of  coniine  slowly  becomes 
crystalline. 

4.  —With  strong  hydrochloric  acid,  or  with  nitric  acid  and 
coniine,  a  pale  red  mixture  is  obtained,  the  color  becoming  darker 
on  standing.  If  the  mixture  be  allowed  to  evaporate  spontan- 


48  QUALITATIVE  ANALYSIS. 

eously,  crystals  separate.  Evaporated  with  sulphuric  acid  a  red 
color  is  developed,  changing  to  green. 

Sparteine,  C15H26N2.  1. — In  general  character  similar  to 
coniine. 

2. — An  etherial  solution  of  iodine  added  to  a  slightly  ammo- 
niacal  etherial  solution  of  sparteine,  separates  minute  dark  green- 
ish-brown crystals. 

NON-VOLATILE    OR    FlXED   ALKALOIDS. 

By  far  the  greater  number  of  alkaloids  belong  to  this  class. 
They  are  mostly  white,  odorless  solids,  fusing  at  a  temperature 
above  100°  C.  without  change,  but  decomposed  when  heated  above 
their  fusing  points. 

Aconitine,  C33H43N012  (crystalline  variety).  1. — A  white 
powder  slightly  soluble  in  cold  water,  more  soluble  in  hot,  soluble 
in  alcohol,  ether  and  chloroform.  A  rapidly  fatal  poison. 

2. — Solutions  of  aconitine  are  precipitated  by  potassium  chro- 
mate,  picric  acid,  and  platinic  chloride.  Mercuric  chloride  and 
potassium  iodide  give  no  precipitates. 

3. — Dissolved  in  aqueous  phosphoric  acid  and  the  solution 
evaporated,  a  violet  color  is  produced. 

4. — With  concentrated  sulphuric  acid  a  yellowish  solution  is 
obtained;  with  nitric  acid,  a  red-brown  solution.  The  colors  ob- 
tained, however,  vary,  and  are  probably  due  to  impurities. 

Atropine,  C17H23N03.  1. — White  crystalline  powder,  spar- 
ingly soluble  in  cold  water,  more  soluble  in  hot  water,  and  easily 
soluble  in  alcohol,  ether  and  chloroform.  The  solutions  are  alka- 
line in  reaction. 

2. — Picric  acid,  and  gold  chloride,  produce  precipitates.  Potas- 
sium iodide,  potassium  chromate,  and  platinic  chloride  give  no 
precipitates.  Mercuric  chloride  precipitates  atropine  from  alcoholic 
solutions. 

3. — Dissolve  a  fragment  of  potassium  dichromate  in  sulphuric 
acid,  add  a  grain  of  atropine  and  a  few  drops  of  water,  and  warm 
the  mixture.  A  pleasing  odor  resembling  that  of  orange  blossoms 
is  developed. 

4. — Moisten  the  alkaloid  with  strong  nitric  acid,  dry  on  the 
water-bath  (=  colorless  residue  with  odor  of  hawthorn)  cool  and 
add  a  few  drops  of  alcoholic  potassium  hydroxide.  A  violet  color 
is  developed,  changing  slowly  to  red. 


TESTS  FOR  THE  COMMON  ALKALOIDS.  49 

5. — Warmed  with  sulphuric  acid,  an  odor  of  hawthorn  is  de- 
veloped. There  should  be  no  change  of  color,  either  with  sul- 
phuric, or  with  nitric  acid. 

6. — The  physiological  test,  dilatation  of  the  pupil,  is  character- 
istic. 

Brucine,  C23H26N204.4H20.  1. — Soluble  in  alcohol  and 
chloroform,  sparingly  soluble  in  water  and  in  ether.  The  physi- 
ological action  is  similar  to  that  of  strychnine,  though  not  so 
•energetic. 

2. — Solutions  of  brucine  are  precipitated  by  potassium  iodide, 
potassium  chromate,  picric  acid,  platinic  chloride,  and  mercuric 
•chloride. 

3. — Chlorine  water  added  slowly  to  a  strong  solution  of  brucine, 
develops  a  red  color,  changed  to  yellowish-brown  by  ammonia. 

4. — Treated  writh  strong  nitric  acid  brucine  is  colored  red,  turn- 
ing to  a  yellow  on  standing.  Addition  of  stannous  chloride 
•changes  the  red  to  a  violet.  (With  morphine,  stannous  chloride 
gives  no  change. ) 

5. — Sulphuric  acid  gives  a  colorless  solution. 

Caffeine  (Theine),  C8H10N402.H20.  1.—  Long  silky  needles, 
soluble  in  water,  more  soluble  in  alcohol.  The  solutions  are 
neutral  in  reaction. 

2. — Mercuric  chloride  gives  a  crystalline  precipitate.  Potassium 
iodide,  potassium  chromate,  picric  acid,  and  platinic  chloride  give 
no  precipitates. 

3. — Dissolve  the  alkaloid  on  a  watch  glass  in  a  few  drops  of  con- 
centrated hydrochloric  acid,  add  a  minute  crystal  of  potassium 
chlorate,  and  evaporate,  gently,  to  dryness.  Add  a  drop  of  dilute 
ammonia,  or  invert  over  a  second  watch  glass  containing  a  few 
drops  of  ammonia.  The  fine  purple  color  so  obtained  is  destroyed 
by  addition  of  sodium  hydroxide. 

4. — Caffeine  forms  colorless  solutions  in  nitric  and  sulphuric  acids. 

Cinchonine,  Cl  9H2  2N20.  1.— Forms  in  white  crystalline  needles 
almost  insoluble  in  water,  slightly  soluble  in  alcohol  and  chloro- 
form, easily  soluble  in  dilute  acids. 

2. — Solutions  of  cinchonine  are  precipitated  by  potassium  iodide, 
potassium  chromate,  picric  acid,  platinic  chloride,  and  mercuric 
chloride. 

3.  —Potassium  ferricyanide  gives  a  precipitate  easily  soluble  in 
excess. 


50  Q  UALITA  TIVE  ANAL  YSIS. 

4. — Chlorine  water  and  bromine  water  give  yellowish-white 
precipitates. 

5. — Colorless  solutions  are  obtained  with  nitric  and  sulphuric 
acids — and  the  solutions  show  no  fluorescence  (unlike  quinine). 

Cocaine,  C17H21N04.  1. — A  white  crystalline  powder,  fusing 
at  98°  C. ,  sparingly  soluble  in  water,  soluble  in  alcohol,  ether  and 
chloroform.  The  solutions  are  strongly  alkaline.  The  hydro- 
chlorate,  C17H21N04HC1,  is  easily  soluble  in  water,  the  solutions 
having  a  slightly  bitter  taste  and  producing  a  tingling  sensation,, 
followed  by  numbness,  on  the  tongue. 

2. — The  alkaloid  is  precipitated  by  picric  acid,  platinic  chloride, 
and  slightly  by  mercuric  chloride.  Potassium  iodide  and  potas- 
sium chromate  give  no  precipitates. 

3. — Add  a  few  drops  of  strong  hydrochloric  acid  and  then  five 
per  cent,  chromic  acid.  An  orange  crystalline  precipitate  is  ob- 
tained on  standing. 

4. — Add,  drop  by  drop,  one  per  cent,  potassium  permanganate. 
Small  violet  colored  crystals  are  formed. 

5. — Solutions  in  nitric  and  sulphuric  acids  should  be  colorless. 

Codeine,  C18H21N03H2O.  1. — Sparingly  soluble  in  water;, 
more  easily  soluble  in  alcohol,  chloroform  and  ether. 

2. — The  solutions  are  precipitated  by  potassium  iodide,  potas- 
sium chromate,  picric  acid,  and  platinic  chloride.  Mercuric 
chloride  gives  no  precipitate. 

3. — With  chlorine  water  a  colorless  solution  is  obtained,  turning 
red  on  addition  of  ammonia. 

4. — Nitric  acid  dissolves  codeine,  giving  a  yellow  solution. 

5. — Concentrated  sulphuric  acid  gives  a  colorless  solution  which 
turns  blue  after  several  days,  or  when  warmed;  best  after  the  ad- 
dition of  a  trace  of  ferric  chloride. 

Gelsemine,  C12H14NO2.  (Gerrard. )  1. — A  colorless,  odorless 
substance,  with  bitter  taste  and  alkaline  reaction.  Very  slightly 
soluble  in  water;  freely  soluble  in  alcohol,  chloroform  and  ether. 

2.  — The  alkaloid  is  precipitated  by  potassium  dichromate,  picric 
acid,  platinic  chloride,  and  mercuric  chloride. 

3. — Nitric  acid  gives  a  nearly  colorless  solution,  but  if  this  be 
allowed  to  evaporate  spontaneously  a  bluish -green  stain  is  left. 

4. — Sulphuric  acid  gives  no  color  with  the  pure  alkaloid.  To 
the  sulphuric  acid  solution  add  a  minute  fragment  of  potassium 
dichromate.  A  reddish-purple  or  cherry-red  color  appears,  and 
the  liquid  acquires  a  greenish-blue  or  blue  color. 


TESTS  FOE  THE  COMMON  ALKALOIDS.  51 

Gelsemic  Acid.  1. — Colorless,  odorless,  nearly  tasteless,  feebly  acid  substance, 
nearly  insoluble  in  water,  soluble  in  ether,  chloroform,  and  alcohol.  Solubility 
in  water  increased  by  presence  of  the  alkaloid. 

2. — With  sulphuric  acid  a  faintly  yellow  solution  is  obtained.  If  a  drop  of 
ammonia  be  placed  in  contact  with  this  solution,  a  copious  crystalline  deposit  will 
form. 

3.— Nitric  acid  dissolves  gelsemic  acid  to  a  yellowish-red  solution,  which  turns 
to  a  deep  red  on  addition  of  ammonia. 

Morphine,  Cj  fHj  9N03.H20.  1. — A  white  crystalline  solid, 
practically  insoluble  in  ether,  chloroform,  and  water,  soluble  in 
boiling  alcohol,  soluble  in  amyl  alcohol,  used  generally  in  form  of 
its  more  soluble  salts. 

2. — Morphine  is  precipitated  by  iodine  in  potassium  iodide, 
potassium  chromate,  picric  acid,  and  platinic  chloride.  Mercuric 
chloride  gives  no  precipitate. 

3.  — Neutral  ferric  chloride,  in  neutral  solutions,  develops  a  blue 
color,  changing  to  green  with  an  excess  of  the  reagent. 

4. — Nitric  acid  produces  a  deep  red  color,  which  gradually  fades 
to  a  yellow.  Addition  of  stannous  chloride  does  not  give  a  violet 
color.  (Unlike  brucine.) 

5. — Sulphuric  acid  forms  a  colorless  solution  which  is  turned  to 
a  green  on  addition  of  a  crystal  of  potassium  dichromate,  or  to  a 
reddish-pink  on  addition  of  a  trace  of  nitric  acid.  The  color  with 
the  dichromate  is  best  obtained  when  strong  acid  has  been  used, 
the  color  with  the  nitric  acid,  best  when  the  sulphuric  has  been 
dilute. 

6. — On  boiling  with  ammonio-cupric  sulphate  the  blue  of  the 
reagent  is  changed  to  a  greenish-blue. 

Meconic  Acid,  C7H4O7.3H2O.     1.— Soluble  in  water,  more  soluble  in  alcohol. 

2.— To  a  drop  of  the  solution  on  a  watch-glass  add  a  drop  of  ferric  chloride.  A 
red  color  appears  which  is  not  destroyed  by  mercuric  chloride  (differing  from 
ferric  sulphocyanate). 

3. _Silver  nitrate  produces  a  white  precipitate  which  turns  red  on  addition 
of  ferric  chloride. 

4. — Barium  chloride  produces  a  white  precipitate. 

Quinine,  C20H24N202.3H20.  Quinine  sulphate,  (C20H24- 
N202)2H2SO47H2O.  Quinine  bimlphate,  C20H24N202.H2S04.- 
7H20.  1.— A  flaky  white  powder  nearly  insoluble  in  water, 
soluble  in  dilute  acids,  in  alcohol,  chloroform,  ether,  etc.  The 
sulphate  is  more  soluble  in  water,  and  the  bisulphate  is  easily 
soluble. 


52  Q  UALITA  TIVE  ANAL  YSIS. 

2. — Quinine  is  precipitated  by  potassium  chromate,  picric  acid, 
platinic  chloride,  and  mercuric  chloride.  Potassium  iodide  gives 
no  precipitate. 

3. — Add  to  an  aqueous  solution  a  few  drops  of  bromine  water, 
or  of  chlorine  water,  and  then  an  excess  of  ammonia.  A  green 
color  is  obtained. 

4. — To  an  aqueous  solution  add  chlorine  water  and  a  little 
potassium  ferrocyanide.  The  solution  turns  pink,  then,  grad- 
ually, red,  best  after  the  addition  of  a  little  ammonia. 

5. — Dissolve  a  few  grains  of  the  alkaloid  in  a  little  dilute  sul- 
phuric acid.  A  blue  fluorescence  is  obtained.  With  concentrated 
nitric  acid,  a  yellowish  solution  showing  a  faint  bluish  fluorescence 
is  obtained. 

Strychnine,  C21H22N202.  1. — White  crystalline  powder,  with 
intensely  bitter  taste  (a  most  dangerous  poison).  Sparingly  sol- 
uble in  alcohol,  and  ether,  almost  insoluble  in  water,  freely  sol- 
uble in  chloroform  and  in  dilute  acids.  The  official  salt  is  the 
sulphate,  (C21H22N202)2H2S04.5H2O. 

2. — Strychnine  is  precipitated  by  potassium  iodide,  potassium 
chromate,  picric  acid,  platinic  chloride,  and  mercuric  chloride. 

3. — Dissolve  a  minute  crystal  of  strychnine  in  one  or  two  drops 
of  strong  sulphuric  acid,  and  draw  through  the  solution,  which 
should  be  colorless,  a  small  fragment  of  potassium  dichromate. 
A  blue  color  is  developed,  rapidly  changing  to  violet,  cherry-red, 
and  finally  to  yellow.  Black  oxide  of  manganese,  potassium  ferri- 
cyanide,  or  potassium  permanganate  may  be  used  in  place  of  the 
dichromate.  The  permanganate,  however,  colors  the  solution, 
and  thus  interferes  with  the  delicacy  of  the  test. 

4. — Dissolved  in  strong  nitric  acid  the  solution  should  be  color- 
less, and  on  evaporation  should  yield  an  odorless  yellow  residue. 
(Compare  with  atropine  and  brucine. ) 

5. — Add  a  drop  of  nitric  acid,  warm,  and  add  a  small  crystal  of 
potassium  chlorate.  A  scarlet  coloration  is  obtained,  turning  to  a 
brown  on  addition  of  ammonium  hydroxide. 

Veratrine,  C32H50N09(?).  1. — White  amorphous,  occasionally 
crystalline,  powder,  bitter  taste,  insoluble  in  water,  soluble  in 
alcohol,  chloroform,  ether,  etc.  When  heated  it  melts  and  gives 
off  acrid  fumes. 

2. — Amorphous  precipitates  are  obtained  with  potassium  iodide, 
potassium  chromate,  picric  acid,  platinic  chloride,  and  mercuric 
chloride. 


SEPARATION  OF  METALS,  ALKALOIDS,  ETC.  53 

3. — Hydrochloric  acid  dissolves  the  alkaloid,  forming  a  colorless 
solution.  On  warming,  a  fragrant  odor  is  developed  and  the  solu- 
tion gradually  turns  red. 

4. — Sulphuric  acid  dissolves  it,  giving  a  solution  yellow  at  first, 
turning  to  an  orange  and  finally  to  carmine-red.  The  solution 
shows  a  partial  green  fluorescence. 

5. — With  nitric  acid  a  yellow  solution  is  obtained. 

The  quantitative  estimation  of  alkaloids  is  described  in  the  section  on 
Volumetric  Analysis. 

GLUCOSIDES,  PTOMAINES,  AND  LEUCOMAINES. 

The  Glucosides,  substances  mostly  of  vegetable  origin,  derive 
their  class  name  from  the  fact  that  one  of  their  decomposition 
products  is  a  glucose  or  similar  body.  In  their  analytical  and 
physiological  properties,  as  well  as  in  their  origin,  they  are  not 
unlike  the  alkaloids,  from  which,  however,  they  differ  in  constitu- 
tion. As  examples  we  may  name:  Amygdalin,  bryonin,  digitalin, 
helleborin,  salicin,  etc. 

The  Ptomaines  may  be  defined  as  basic  compounds  formed  by 
the  action  of  bacteria  on  nitrogenous  organic  matter.  Though 
differing  from  the  alkaloids  in  origin,  they  are  alkaloidal  in  nature, 
and  simulate  the  true  alkaloids  in  their  behavior  with  reagents. 
They  are  not  to  be  confused  with  those  other  products  of  bacterial 
action,  the  Bacterial  Proteids;  and  the  Toxines  of  disease,  nor  with 
the  similar  Serpent  Venoms.  As  examples  of  the  ptomaines  we 
have:  Putrescine,  cadaverine,  neurine,  typhotoxine,  mytilotoxine 
and  tyrotoxicon. 

The  Leucomaines  are  alkaloidal  products  of  normal  body  meta- 
bolism, and  are  exam  pled  by  adenine,  xanthine,  hypoxanthine, 
carnine,  spermine,  and  xantho-creatinine. 

SEPARATION  OF  METALS,  ALKALOIDS,  ETC.,  FROM 
ORGANIC  MATTER. 

The  special  tests  given  for  the  metals  and  alkaloids  are,  as  a 
rule,  applicable  only  in  absence  of  organic  matter.  When,  as  is 
often  the  case,  an  organ,  a  tissue,  or  an  organic  fluid  is  presented 
for  examination,  it  becomes  necessary  to  either  remove  or  destroy 
the  organic  matter  before  proceeding  with  the  analysis.  Many 
processes  have  been  proposed,  but  all,  though  simple  in  theory, 
require  expert  chemical  knowledge  for  their  successful  application. 


54  Q  UALITA  TIVE  ANAL  YSIS. 

The  methods  given  below  for  metals  are  particularly  adapted  to 
the  separation  of  arsenic,  but  apply  with  slight  modifications  to 
all  of  the  metallic  poisons. 

SEPARATION  OF  METALS.  Method  of  Fresenius  and  Babo. — The 
solid  matter  is  finely  divided  and  treated  with  an  equal  weight  of  a 
mixture  of  pure  hydrochloric  acid  (1  part)  and  water  (3-4  parts). 
The  mixture  is  then  digested  on  a  water-bath  and  small  quantities 
of  potassium  chlorate  added  from  time  to  time.  When  the  solid 
matter  has  been  entirely  decomposed  the  clear  yellow  liquid  is 
evaporated,  until  the  odor  of  chlorine  has  disappeared,  or  the 
chlorine  is  removed  by  passing  carbon  dioxide  gas  through  the 
solution.  The  solution  is  now  filtered  and  examined,  by  the  usual 
tests,  for  the  metals;  in  the  case  of  arsenic,  best  after  reduction  by 
sulphur  dioxide  and  subsequent  warming  to  remove  the  excess  of 
the  gas. 

By  Distillation. — In  the  case  of  arsenic,  and  of  certain  volatile 
compounds  of  metallic  poisons,  the  following  method  may  be 
used:  The  finely  divided  organic  matter  is  dried  on  the  water- 
bath,  mixed  with  its  own  weight  of  pure  hydrochloric  acid  and 
distilled  from  a  glass  retort  provided  with  a  condenser.  The  dis- 
tillate is  received  in  cold  water,  and  may  be  examined  at  once  for 
poisons. 

By  Dialysis. — The  finely-cut  material  is  digested  in  cold  water — 
or  in  dilute  acid — for  24  hours,  and  then  placed  in  a  dialyzer. 
The  latter  is  suspended  in  a  larger  vessel  containing  distilled  water, 
and  at  the  end  of  another  24  hours  the  water  is  evaporated  and 
the  residue  examined  for  poisons.  This  method  is  applicable  also 
to  the  separation  of  the  alkaloids. 

SEPARATION  OF  ALKALOIDS,  GLUCOSIDES,  ETC.  The  separation  of 
the  alkaloids  from  organic  matter  is  one  of  the  most  difficult  and, 
on  the  whole,  one  of  the  most  unsatisfactory  problems  of  chemical 
toxicology.  The  following  outlines  will  indicate  the  general  nature 
of  the  processes  used: 

Stas-Otto  Method. — Treat  the  finely  comminuted  mass  with  twice 
its  weight  of  pure  90  per  cent,  alcohol,  and  with  10  to  30  grains  of 
oxalic  acid.  Digest  at  70°  C.,  and  filter.  Evaporate  the  filtrate 
in  vacuo,  over  sulphuric  acid,  dissolve  the  residue  in  absolute 
alcohol,  filter,  and  again  evaporate  at  a  low  temperature.  Dissolve 
in  water  and  extract  with  ether  until  all  coloring  matter  is  re- 
moved, then  add  sodium  carbonate  to  alkaline  reaction,  again 


SEPARATION  OF  METALS,  ALKALOIDS,  ETC.  55 

agitate  with  ether,  and  separate  the  etherial  layer.  Allow  the 
ether  to  evaporate  spontaneously  and  examine  the  residue  for 
alkaloids.  With  the  coloring  matter  the  first  etherial  extract  may 
contain  colchicine,  digitalin  and  picrotoxin.  Most  of  the  alkaloids 
will  pass  into  the  second  extract,  that  from  the  alkaline  solution; 
morphine,  however,  being  nearly  insoluble  in  ether,  will  remain, 
and  should  be  examined  for  by  extraction  of  the  alkaline  solution 
with  amyl  alcohol. 

Dragendorff's  Method. — This  method  is  convenient,  as  affording 
a  partial  separation  of  the  alkaloids  during  their  extraction.  The 
finely  divided  substance  is  digested  for  several  hours  with  water 
acidulated  with  sulphuric  acid.  The  extract  is  removed  and  the 
process  repeated,  the  temperature  being  maintained  at  from  40°  C. 
to  50°  C.  The  extracts  are  united,  evaporated  to  a  syrup,  and 
digested  with  4  volumes  of  alcohol  for  24  hours  at  30°  C.  The 
alcoholic  extract  is  filtered,  the  residue  washed  with  70  per  cent, 
alcohol,  and  the  united  extracts  freed  from  alcohol  by  evaporation. 
The  aqueous  residue,  diluted  if  necessary,  is  filtered,  and  the  acid 
liquid,  containing  the  sulphates  of  the  alkaloids,  treated  with  the 
following  reagents: 

1. — Agitate  with  petroleum  ether,  remove  etherial  layer,  repeat 
extraction,  evaporate  extracts.  Residue  consists  chiefly  of  coloring 
matters,  but  may  contain,  also,  piperine,  picric  acid,  camphor, 
phenol,  etc. 

2. — Extract  with  benzene.  Evaporate  extract.  Residue,  if 
crystalline,  may  be  cantharidin,  santonin,  or  digitalin,  caffeine, 
piperine,  or  berberine;  if  amorphous,  elaterin,  populin,  colocynthin, 
or  colchicine. 

3. — Extract  with  chloroform.  Evaporate  extract.  Residue 
may  be  digitalin,  picrotoxin,  helleborin,  saponin,  cinchonine,  or  theo- 
bromine. 

4. — Treat  again  with  petroleum  ether,  remove  etherial  layer, 
render  alkaline  with  ammonia.  Treat  the  alkaline  solution  with 
petroleum  ether,  remove  and  evaporate  the  extract.  Residue  may 
be  strychnine,  quinine,  brucine,  veratrine,  coniine,  nicotine,  sparteme, 
or  aniline. 

5. — Extract  the  alkaline  solution  with  benzene.  Evaporate  ex- 
tract. Residue  may  be  strychnine,  brucine,  quinine,  cinchonine, 
atropine,  hyoscyamine,  physostigmine,  aconitine,  codeine,  thebaine, 
narceine,  narcotine,  or  veratrine. 


56  Q  UALITA  TIVE  ANAL  YSIS. 

6. — Extract  with  chloroform.  Evaporate  extract.  Residue  may 
be  morphine,  cinchonine,  papaverine,  or  narceine. 

7. — Extract  with  amyl  alcohol.  Evaporate  extract.  Residue 
may  be  morphine,  solanine,  or  salicin. 

8. — Evaporate  remainder  of  the  solution  with  powdered  glass. 
Extract  with  chloroform.  Evaporate  extract.  Residue  may  be 
curarine. 


VOLUMETRIC  QUANTITATIVE  ANALYSIS. 


QUANTITATIVE  analyses  may  be  conducted  by  either  gravimetric 
or  volumetric  processes.  In  the  former,  the  constituents  are  pre- 
cipitated from  solutions  by  reagents,  the  precipitates  are  dried  and 
weighed,  and  from  their  weights  the  composition  of  the  substance 
is  calculated.  Volumetric  analyses  are,  as  a  rule,  more  quickly 
performed  and  require  less  extensive  laboratory  appliances.  The 
process,  depending  on  the  principle  of  Definite  and  Fixed  Propor- 
tions in  chemical  combinations,  consists  in  the  determination  of 
the  amount  of  a  substance  in  solution  by  the  addition  thereto  of  a 
reagent  of  known  strength,  the  standard  solution.  The  reagent  is 
added  from  an  accurately  graduated  glass  vessel,  known  as  a 
burette,  and  the  end  of  the  reaction  is  revealed  either  by  a  change 
in  the  liquid  itself,  or  by  a  change  in  color  of  a  substance  added 
as  an  indicator. 

The  reaction  between  sulphuric  acid  and  potassium  hydroxide 
is  expressed  by  the  equation: 

2KOH  +  H2S04  =  K2S04  +  2H20 

*  Molecular  Weights,  2)111.98    2)97.82 

55.99       48.91 

If  sulphuric  acid  be  added  to  a  solution  of  potassium  hydroxide, 
the  solution  will  remain  alkaline  until  sufficient  acid  has  been 
added  to  complete  the  above  reaction.  In  other  words,  to  111.98 
parts  of  potassium  hydroxide  we  must  add  97.82  parts  of  sul- 
phuric acid,  in  order  that  complete  neutralization  shall  take  place. 
If  more  acid  be  added,  the  solution  will  become  acid  in  reaction. 

*  The  equivalents  (molecular  weights)  given  in  this  section  are  those  generally 
used  in  the  United  States  by  pharmacists.  Where  more  exact  values  are  desired 
the  equivalents  may  be  simply  calculated  from  the  list  of  atomic  weights  on  page 
8  of  this  book. 

(57) 


58  VOL  UMETRIC  ANAL  YSIS. 

If  97.82  grammes  of  sulphuric  acid  exactly  neutralize  111.98 
grammes  of  potassium  hydroxide,  then  if  we  make  a  solution 
containing  98.72  grammes  of  sulphuric  acid  in  1000  c.c. ,  each  c.c. 
of  this  solution  will  neutralize  0.11198  grammes  of  potassium  hy- 
droxide. So,  also,  in  a  solution  containing  48.91  grammes  of  the 
acid  to  1000  c.c.,  each  c.c.  will  neutralize  0.05599  grammes  of  the 
alkali.  If  now  to  a  solution  of  potassium  hydroxide  of  unknown 
strength  we  add  a  standard  solution  of  sulphuric  acid  (one  con- 
taining a  known  weight  of  the  acid  in  each  c.c.)  until  neutraliza- 
tion is  effected,  we  can  calculate  the  amount  of  alkali  from  the 
number  of  c.c.  of  acid  used. 

Again,  were  we  to  add  a  standard  solution  of  sodium  chloride  to 
a  solution  of  silver  nitrate,  the  reaction  would  be  expressed  by  the 
equation : 

AgN08  +  Nad  =  AgCl  4  NaN03 

Molecular  Weights,  169.55       58.37 

The  number  of  c.c.  of  standard  sodium  chloride  necessary  to 
complete  the  above  reaction  (to  precipitate  all  of  the  silver  as 
silver  chloride)  affords  us  the  means  of  calculating  the  amount  of 
silver  nitrate  in  the  solution.  The  same  principle  may  be  applied 
in  other  ways,  as,  for  instance,  in  the  determination  of  the  amount 
of  iron  in  a  solution.  We  may  first  reduce  the  iron  to  the  ferrous 
state  by  appropriate  reducing  agents,  and  then  by  the  addition  of 
a  solution  of  known  oxidizing  power,  we  may  reconvert  the  iron 
to  the  ferric  condition.  The  number  of  c.c.  of  oxidizing  solution 
used,  multiplied  by  the  oxidizing  power  of  each  c.c.,  affords  the 
data  necessary  for  the  calculation  of  the  iron  present. 

SOLUTIONS  USED. 

In  order,  then,  to  make  a  quantitative  determination  of  a  sub- 
stance by  a  volumetric  process,  we  must  have  an  appropriate 
reagent,  of  known  strength,  a  standard  solution.  The  strength  of 
this  reagent  will  be  determined  by  the  nature  of  the  analysis,,  but 
it  is  convenient  that  the  weight  in  grammes,  dissolved  in  each  litre, 
shall  bear  an  intimate  relation  to  the  molecular  weight,  thus  sim- 
plifying subsequent  calculations.  The  solutions  most  commonly 
used  are  designated  as  Normal,  (  Y  ),  Deci-Normal,  (y^),  and 
Centi-Normal,  (T|-g-). 


VOL  UMETRIC  ANA  L  YSIS.  59 

A  Normal  Solution  of  a  univalent  substance  contains,  in  each 
litre,  its  molecular  weight  expressed  in  grammes. 

A  Normal  Solution  of  a  bivalent  substance  contains,  in  each 
litre,  -^  its  molecular  weight  expressed  in  grammes. 

A  Normal  Solution  of  a  trivalent  substance  contains,  in  each 
litre,  J  its  molecular  weight  expressed  in  grammes. 

A  Deci-Normal  Solution  is  y^th  the  strength  of  the  correspond- 
ing normal  solution. 

A  Centi-Normal  Solution  is  T^th  the  strength  of  the  corre- 
sponding normal  solution. 

For  example  1  litre  of  y  KOH  (normal  potassium  hydroxide) 
contains  55.99  grammes  of  KOH.  One  litre  of  T^  KOH  contains 
5.599  grammes  of  KOH.  One  litre  of  T|7  KOH  contains  0.5599 
grammes  of  KOH.  One  litre  of  y  H2S04  contains  48.91  grammes 
of  H2S04  (molecular  weight  of  bivalent  H2S04  =97.82).  One 
litre  of  yjy  H2S04  contains  4.891  grammes  of  H2SO4,  etc. 

Indicators. — The  success  of  the  volumetric  process  depends  upon 
the  accuracy  with  which  we  determine  the  completion  of  the 
chemical  reaction  between  the  reagent  and  the  substance  under 
titration.  This  is  generally  accomplished  by  adding  to  the  solu- 
tion a  substance  wrhich  will  reveal  by  change  of  color  the  slightest 
excess  of  the  reagent,  The  substance  so  used  is  known  as  an 
indicator,  and  must  answer  to  the  following  conditions:  The  com- 
pletion of  the  test,  the.  end  reaction,  must  be  marked  by  an  indis- 
putable change  in  color;  but  little  of  the  indicator  should  be  used, 
and  the  color  change  must  not  be  interfered  with  by  any  impuri- 
ties present,  nor  by  the  products  of  the  reaction  itself.  The  fol- 
lowing are  some  of  the  indicators  in  common  use.  For  their 
preparation,  see  Appendix. 

Litmus.  —  Red  with  acids,  blue  with  alkalies.  Litmus  is  used 
chiefly  in  the  titration  of  the  mineral  acids  and  alkalies;  it  is  not 
reliable  as  an  indicator  in  presence  of  carbonates,  phosphates  or 
arsenates. 

Phenolphthalein. — Colorless  with  acids,  red  with  alkalies.  This 
indicator  is  much  used  and  is  extremely  delicate,  but  its  value  is 
lessened  by  presence  of  ammonium  salts  or  of  borax. 

When  it  is  necessary  to  use  phenolphthalein  or  litmus  in  pres- 
ence of  carbonic  acid  (carbonates),  the  solution  under  titration 
should  be  boiled. 

Methyl  Orange.— Red  with  acids,  yellow  with  alkalies.     It  is  not 


60  VOL  UMETRIC  ANAL  YSIS. 

affected  by  carbonic  anhydride,  and  hence  may  be  used  in  pres- 
ence of  carbonates,  but  it  is  not  satisfactory  with  organic  acids. 

Cochineal — Yellow  with  acids,  violet  with  alkalies.  Used  chiefly 
with  ammonia  and  ammonium  compounds. 

Other  special  indicators  will  be  referred  to  in  describing  certain 
of  the  processes  which  follow. 

ACIDIMETKY. 

The  estimation  of  acids  by  means  of  standard  alkali  solutions. 
Sodium  or  potassium  hydroxides  are  the  alkalies  generally  used, 
the  standard  solutions  being  prepared  as  follows: 

Normal  Potassium  Hydroxide. — If  pure  potassium  hydroxide  were 
obtainable  it  would  only  be  necessary  to  dissolve  55.99  grammes 
of  that  substance  in  1  litre  of  water.  (55.99  being  the  molecular 
weight  of  univalent  potassium  hydroxide.)  It  can  not  be  ob- 
tained pure,  however,  owing  to  its  tendency  to  absorb  carbonic 
anhydride  and  moisture  from  the  air,  and  the  following  U.  S.  P. 
method  is  advised:  Dissolve  75  grammes  of  potassium  hydroxide 
in  1050  c.c.  of  water  at  15°  C.,  and  fill  a  burette  with  this  solu- 
tion. Dissolve  0. 63  grammes  of  pure  crystallized  oxalic  acid  in 
about  10  c.c.  of  water  and  add  a  few  drops  of  phenolphthalein. 
Now  add  the  potassium  hydroxide,  from  the  burette,  until  the 
oxalic  acid  is  just  neutralized,  a  faint  pink  tint  being  developed  in 
the  solution.  Note  the  number  of  c.c.  of  alkali  used,  and  then 
dilute  the  remainder  of  the  solution  until  10  c.c.  will  exactly 
neutralize  the  0.63  grammes  of  oxalic  acid.  The  reaction  between 
the  alkali  and  acid  is  expressed  by  the  equation: 

2KOH  +  H2C204.2H20  «  K2C204  +  4H20 

Molecular  weights,   112  126 

From  this  it  can  be  seen  that  126  parts  of  oxalic  acid  are 
neutralized  by  112  parts  of  potassium  hydroxide,  or  63  parts  by 
56  of  potassium  hydroxide.  Normal  potassium  hydroxide  con- 
tains 56  grammes  to  the  litre,  and  10  c.c.  of  the  normal  solution 
contain  0.56  grammes.  Hence,  in  the  preparation  of  the  normal 
alkali  as  described,  when  10  c.c.  exactly  neutralizes  0.63  grammes 
of  oxalic  acid,  then  that  10  c.c.  must  contain  0.56  grammes  of 
potassium  hydroxide,  and  the  solution  must  be  normal. 

Deci-Normal  Potassium  Hydroxide. — Dilute  100  c.c.  of  the  normal 
solution  to  1000  c.c.,  with  pure  water. 


VOL  UMETRIC  ANALYSIS.  61 

Normal  Sodium  Hydroxide.—  This  contains  39.96  (40)  grammes 
of  sodium  hydroxide  to  the  litre.  The  solution  is  prepared  by 
dissolving  54  grammes  of  sodium  hydroxide  in  1050  c.c.  of  water, 
proceeding,  then,  exactly  as  described  under  potassium  hydroxide! 
The  reaction  in  this  case  is  expressed  by  the  equation: 

2  NaOH  +  H2C204.2  H20  =  Na2C204  +  4  H20. 


Each  Cubic  Centimeter  of  a  Normal  Alkali  Solution  is  equivalent  to  : 

Grammes. 

Acetic,  HC2H302       ....  0.05986 

Citric,  H3C6H507.H20      .         .         .  0.06983 

Hydrobromic,  HBr    ....  0.08076 

Hydrochloric,  HC1     ....  0.03637 

Hydriodic,  HI   .....  0.12753 
Lactic,  HC3H503       .....  0.08979 

Nitric,  HN03     .....  0.06289 

Oxalic,  H2C204.2H20        .         .         .  0.06285 

Sulphuric,  H2S04      ....  0.04891 

Tartaric,  H2C4H406           .         .         .  0.07482 

Method  of  Analysis.  —  A  weighed  quantity  of  the  acid  is  diluted 
with  a  little  water,  a  few  drops  of  phenolphthalein  added,  and 
then  the  standard  alkali,  from  a  burette,  until  a  faint  pink  tint  is 
developed.  The  number  of  c.c.  of  standard  solution  used,  multi- 
plied by  the  equivalent  of  each  c.c.  gives  the  weight  of  pure  acid 
in  the  solution.  From  this,  and  the  weight  of  the  sample,  the 
percentage  may  be  calculated. 

If  5  grammes  of  hydrochloric  acid  solution  were  taken  for 
analysis,  and  20  c.  c.  of  normal  alkali  were  required  to  develop  the 
pink  color,  then  the  5  grammes  of  acid  solution  contain,  20  X 
0.03637  =  0.7274  grammes  of  pure  acid,  or,  0.  7274-5  X  100  = 
14.55  per  cent. 

Remarks.  —  It  is  often  inconvenient  to  weigh  the  sample  taken 
for  analysis,  and  in  such  a  case,  a  definite  volume  must  be  used. 
The  titration  with  the*  normal  solution  will  give  the  number  of 
grammes  of  pure  substance  in  the  sample,  and  for  many  solutions 
we  can  assume  the  weight  of  the  sample  to  be  equal  to  as  many 
grammes  as  there  were  c.c.  taken.  (1  c.c.  of  water  weighs  1 
gramme.  )  Or,  we  can  determine  the  specific  gravity  of  the  solu- 


62  VOLUMETRIC  ANALYSIS. 

tion  by  means  of  a  hydrometer,  and  calculate  the  weight  of  the 
sample  by  multiplying  its  volume  by  its  specific  gravity. 

The  pharmacopceial  practice  is  to  weigh  off  such  a  quantity  of 
the  substance,  for  analysis,  that  the  number  of  c.c.  of  standard 
solution  used  will  directly  express  the  percentage  sought.  Thus, 
3.64  grammes  of  U.  S.  P.  acidum  hydrochloricum,  containing 
31.9  percent,  of  pure  hydrochloric  acid,  will  be  exactly  neutral- 
ized by  31.9  c.c.  of  normal  alkali.  3.64  grammes  of  the  dilute 
acid  of  the  Pharmacopoeia,  containing  10  per  cent,  of  pure  acid, 
will  be  exactly  neutralized  by  10  c.c.  of  normal  alkali. 

The  method  is,  in  general,  the  same  for  any  acid,  merely  sub- 
stituting in  the  calculation  the  proper  equivalent  for  each  c.c.  of 
the  standard  alkali  used. 

ALKALIMETRY. 

The  estimation  of  alkalies  by  means  of  a  standard  acid  solution. 
Several  of  the  acids  are  used  for  this  purpose,  the  more  common 
being  oxalic,  sulphuric  and  hydrochloric.  Oxalic  acid  has  the 
distinct  advantage  over  the  others  of  easy  preparation,  but,  as  a 
rule,  sulphuric  acid  will  be  found  to  have  the  widest  application 
and  to  give  the  most  satisfactory  results. 

Normal  Oxalic  Acid. — Dissolve  62.85  grammes  of  the  pure 
crystalline  acid  in  water  and  dilute  to  1  litre.  (62.85  being  J  the 
molecular  weight  of  the  bivalent,  crystalline  oxalic  acid. ) 

Deci-Normal  Oxalic  Acid. — Dilute  100  c.c.  of  the  normal  acid  to 
1000  c.c.  with  water;  or,  dissolve  6.285  grammes  of  the  acid  in 
water  and  dilute  to  1  litre. 

Genii-Normal  Oxalic  Acid. — Dilute  10  c.c.  of  the  normal  acid  to 
1000  c.c.  with  water;  or,  dissolve  0.6285  grammes  of  the  acid  in 
water  and  dilute  to  1  litre. 

Normal  Sulphuric  Acid. — The  normal  solution  of  sulphuric  acid 
contains  48.91  grammes  in  1  litre.  (48.91  being  -J  the  molecular 
weight  of  the  bivalent  acid.)  It  is  prepared  by  mixing  30  c.c  of 
pure  concentrated  acid,  specific  gravity  1.835,  with  enough  water 
to  make  1050  c.c.  The  mixture  is  cooled. and  its  strength  deter- 
mined by  titration  with  normal  potassium  hydroxide.  It  is  then 
diluted  with  water  until  10  c.c.  will  exactly  neutralize  10  c.c.  of 
the  normal  alkali;  in  other  words,  until  each  c.c.  contains  0.04891 
grammes  of  pure  sulphuric  acid. 


VOLUMETRIC  ANALYSIS.  63 

Each  Cubic  Centimeter  of  a  Normal  Acid  Solution  is  equivalent  to  : 

Grammes. 

Ammonia  gas,  NH3 0.01701 

Ammonium  hydroxide,  NH4OH           .         .  0.03497 

Lithium  carbonate,  Li2C03           .         .         .  0.03693 

Potassium  bicarbonate,  KHC03   .         .         .  0.09988 

Potassium  carbonate,  K2C03        .         .         .  0.06895 

Potassium  hydroxide,  KOH          .         .         .  0.05599 

Sodium  bicarbonate,  NaHC03      .         .         .  0.08385 

Sodium  carbonate,  Na2C03           .         .         .  0.05292 

Sodium  hydroxide,  NaOH  .  0.03996 

Method  of  Analysis. — A  weighed  quantity  of  the  sample  is  diluted 
with  water,  or,  if  solid,  is  dissolved  in  water,  a  few  drops  of  phenol- 
phthalein  added,  and  the  standard  acid  run  in  from  a  burette  until 
the  pink  color  of  the  solution  is  just  destroyed.  The  number  of 
c.c.  of  standard  acid  used,  multiplied  by  the  equivalent  of  each 
c.c.,  gives  the  weight  of  pure  alkali  in  the  solution.  From  this, 
and  the  weight  of  the  sample,  the  percentage  can  be  calculated. 

If  5  grammes  of  sodium  hydroxide  solution  were  taken  for 
analysis,  and  25  c.c.  of  normal  sulphuric  acid  were  required  to 
effect  neutralization,  then  the  5  grammes  of  alkali  solution  contain 
25X0.03996  =  0.999  grammes  of  pure  sodium  hydroxide,  or, 
0.999  -*-  5  X  100  =  19.98  per  cent. 

Remarks. — In  the  titration  of  carbonates,  methyl  orange  is  to  be 
used  as  the  indicator,  the  standard  acid  being  added  until  the 
solution  acquires  a  faint  orange-red  tint.  Otherwise  the  process  is 
as  described.  The  remarks  on  p.  61  are  also  applicable  here. 

ESTIMATION  OF  HALOID  SALTS. 

Salts  of  chlorine,  bromine  and  iodine,  may  be  conveniently  esti- 
mated by  precipitation  with  a  standard  solution  of  silver  nitrate. 
The  reagent  is  added  until  all  of  the  halogen  has  been  precipitated 
as  silver  salt,  and  from  the  number  of  c.c.  used  the  original 
halogen  compound  may  be  calculated.  The  completion  of  the 
reaction  may  be  determined  by  testing  small  portions  of  the  solu- 
tion from  time  to  time,  filtering  off  the  precipitate  and  adding  a 
drop  of  silver  nitrate,  until  no  further  precipitation  occurs.  Much 
more  satisfactorily,  however,  we  can  add  to  the  solution  a  few 
drops  of  potassium  chromate,  which,  by  formation  of  red  silver 


64  VOL UMETRIC  ANALYSIS. 

chromate  when  all  of  the  halogen  has  been  precipitated,  will  reveal 
the  slightest  excess  of  the  silver  nitrate. 

Deci-Normal  Silver  Nitrate. — Dissolve  16.955  grammes  of  pure 
silver  nitrate  in  water  and  dilute  to  1  litre,  at  15°  C.  (The 
molecular  weight  of  silver  nitrate  being  169.55,  the  deci-normal 
solution  will  contain  -J^th  of  the  molecular  weight,  expressed  in 
grammes. )  The  solution  should  be  kept  in  the  dark. 

Should  pure  silver  nitrate  not  be  available,  a  trial  solution 
stronger  than  the  deci-normal  is  first  prepared,  and  then  0.1167 
grammes  of  pure  sodium  chloride  is  dissolved  in  water  and 
titrated.  Were  the  silver  nitrate  deci-normal,  20  c.c.  would  ex- 
actly precipitate  all  of  the  chlorine  of  the  salt  as  silver  chloride; 
but  as  the  solution  is  stronger  than  deci-normal,  less  than  20  c.c. 
will  complete  the  reaction.  Determine  the  exact  strength  of  the 
strong  silver  nitrate  and  dilute  with  such  a  quantity  of  water  as 
will  reduce  it  to  the  strength  required,  i.  e. ,  to  the  deci-normal. 

Each   Cubic   Centimeter  of  Deci-Normal  Silver  Nitrate  Solution  is 

equivalent  to : 

Grammes. 

Ammonium  Bromide,  NH4Br    .         .         .  0.009777 

Chlorine,  Cl                                    ...  0.003537 

Lithium  Bromide,  LiBr      ....  0.008677 

Potassium  Bromide,  KBr  ....  0.011879 

Potassium  Chloride,  KC1    ....  0.007440 

Potassium  Cyanide,  KCN  ....  0.013002 

Potassium  Iodide,  KI  0.016556 

Sodium  Bromide,  NaBr      ....  0.010276 

Sodium  Chloride,  NaCl       ....  0.005837 

Zinc  Chloride,  ZnCl2           ....  0.006792 

Method  of  Analysis.  — To  a  measured  volume  of  the  salt  solution, 
or  to  a  weighed  quantity  of  the  salt  dissolved  in  water,  add  a  few 
drops  of  neutral  potassium  chromate,  and  then  the  deci-normal 
silver  nitrate,  from  a  burette,  until  the  solution  acquires  a  slight 
but  permanent  red  tinge.  The  number  of  c.c.  of  the  deci-normal 
solution  used,  multiplied  by  the  equivalent  of  each  c.c.,  gives  the 
weight  of  the  halogen  salt  in  solution.  From  this  and  the  weight 
of  the  sample,  the  percentage  strength  can  be  calculated. 

In  titrating  potassium  cyanide,  no  indicator  is  used,  but  the 
silver  nitrate  is  added  until  the  appearance  of  the  first,  slight,  per- 
manent precipitate. 


VOLUMETRIC  ANALYSIS. 


65 


ESTIMATION  OF  ALKALOIDS. 

By  Mayer' s  Solution. — (See  Appendix.)  The  weighed  alkaloid 
is  dissolved  in  water  acidulated  with  sulphuric  acid  and  the 
Mayer's  solution  added  from  a  burette  until  all  is  precipitated. 
Alcohol,  acetic  acid,  and  ammonia  all  interfere  with  the  test,  but 
the  results,  at  the  best,  are  only  approximate.  Each  c.c.  of  the 
solution  will  precipitate  the  following  weights  of  the  alkaloids: 


Grammes. 

Aconitine   0.0269 

Atropine 0.0090 

Brucine 0.0197 

Cinchonine 0.0102 

Cocaine  0.0151 

Codeine 0.0149 


Grammes. 

Coniine 0.0125 

Morphine 0.0200 

Nicotine 0.0040 

Quinine 0.0108 

Sparteine 0.0028 

Strychnine   0.0167 


By  Standard  Acid  and  Alkali  Solutions. — The  free  alkaloid  is  dis- 
solved in  a  measured  amount  of  •£§  HC1,  and  the  excess  of  acid, 
over  that  which  combines  with  the  alkaloid,  determined  by  titra- 
tion  with  -^  NaOH,  using  phenolphthalein  as  the  indicator. 

The  following  direct  method  may  also  be  employed:  Dissolve 
the  alkaloid  in  a  little  chloroform,  add  a  few  c.c.  of  water,  and 
then  titrate  with  -/-$  HC1,  using  methyl  orange  as  the  indicator, 
and  agitating  after  each  addition  of  acid. 

Salts  of  the  alkaloids  may  be  titrated  directly  with  -^  NaOH, 
using  either  phenolphthalein  or  methyl  orange  as  an  indicator. 

Each  c.c.  of  the  -^  acid  or  alkali  is,  theoretically,  equivalent  to: 


Grammes. 

Aconitine    0.0323 

Atropine 0.0144 

Brucine 0.0197 

Cinchonine 0.0147 

Cocaine 0.0151 

Odeine 0.0149 


Grammes. 

Coniine 0.0062 

Morphine 0.0142 

Nicotine  0.0040 

Quinine 0.0162 

Sparteine 0.0028 

Strychnine 0.0167 


Special  Volumetric  Processes,  applicable  in  urine  analysis,  in 
the  analysis  of  the  gastric  fluid,  water,  etc. ,  are  described  in  the 
•clinical  section  of  this  book. 


PART  II. 


THE  CARBOHYDRATES,  PROTEIDS, 

AND  FATS, 
FERMENTS  AND  FERMENTATION. 


THE  CARBOHYDRATES. 


THE  carbohydrates,  an  important  group  of  compounds,  are 
chiefly  of  vegetable  origin,  but  occur,  also,  in  the  animal  tissues 
and  fluids.  They  may  be  classified  as  follows: 


Monosaccharids, 
or  Glucoses. 


Disaccharids, 
or  Sucroses. 


Dextrose  (Glucose),  Sucrose  (Cane  Sugar), 
Levulose  (Fruit  Sugar),  Lactose  (Milk  Sugar), 
Galactose, 
Mannose, 


Sorbose. 


Maltose, 
Mycose, 
Rafnnose. 


Polysaccharids, 
or  Amyloses. 

(C,H,,0.).. 

Cellulose, 

Starch, 

Granulose, 

Dextrin, 

Glycogen. 


Chemically  the  glucoses  may  be  considered  as  aldehydes  and 
ketones  derived  from  hexatomic  alcohols.  The  amyloses  and 
sucroses  may  be  regarded  as  anhydrides  of  the  glucoses. 

By  oxidation  carbohydrates  are  converted  into  mannitic  acid, 
and,  by  further  oxidation,  into  mucic  and  saccharic  acids,  tartaric 
acid,  oxalic  acid  and  carbonic  acid.  By  oxidation  in  presence  of 
an  alkali,  carbohydrates  are  converted  into  glucic  and  melassic 
acids. 

DEXTROSE.     (Glucose,  Grape  Sugar,  etc. ) 

A  white  powder,  more  or  less  crystalline,  soluble  in  water,  less 
soluble  in  alcohol,  insoluble  in  ether.  It  is  sweet  to  the  taste,  but 
less  so  than  cane  sugar.  This  sugar  is  found  in  fruits,  in  h6ney, 
and,  in  small  amount,  in  the  various  fluids  of  the  body.  In 
diseased  conditions  it  may  appear  in  the  body  fluids  in  largely 
increased  amount. 

1. — Moore1  s  Test. — Add  to  a  dilute  solution  of  glucose  one-half 
volume  of  sodium  hydroxide,  and  heat  to  boiling.  A  brown  col- 
oration is  obtained.  Add  a  little  nitric  acid,  the  color  disappears 
in  part  and  the  characteristic  odor  of  caramel  is  given  off. 

(69) 


70  CARBOHYDRATES. 

2. — Picric  Acid  Test. — Add  to  the  solution  a  few  drops  of  picric 
acid  and  a  little  sodium  hydroxide.  Heat  the  mixture  and  a 
mahogany-brown  color  is  developed. 

3. — Silver  Test. — To  some  ammonio-silver  nitrate  add  a  few  grains 
of  glucose.  When  dissolved,  heat  to  boiling.  The  solution  turns 
dark  and  a  metallic  mirror  of  silver  is  formed  at  the  bottom  of  the 
tube.  Tartaric  acid  and  aldehyde  each  give  the  same  test. 

4. — Fermentation  Test. — To  the  solution  in  a  test-tube  add  a  small 
piece  of  dry  yeast  and  invert  the  tube  over  mercury.  After  stand- 
ing for  24  hours  in  a  warm  place,  carbonic  anhydride  gas  will  be 
found  to  have  accumulated  at  the  top  of  the  tube.  The  liquid  may 
be  tested  for  alcohol.  It  is  well  to  make  a  control  test  with  yeast 
and  pure  water  in  a  second  test-tube. 

5. — Bottger's  Test. — To  the  solution  of  glucose  in  a  test-tube  add 
sodium  hydroxide  and  then  a  few  grains  of  bismuth  subnitrate. 
Mix  the  solution  well  and  heat  to  boiling.  A  black  precipitate  of 
metallic  bismuth  is  formed.  Sodium  carbonate  may  be  used  in 
place  of  sodium  hydroxide. 

6. — Trammer's  Test. — To  the  solution  add  an  excess  of  sodium 
hydroxide,  and  then  a  solution  of  copper  sulphate  drop  by  drop, 
until  a  slight  permanent  precipitate  is  formed.  In  the  presence  of 
glucose  the  bluish-white  precipitate  of  cupric  hydroxide  first 
formed  dissolves  on  agitation,  producing  a  dark  blue  solution. 
Heat  the  liquid  and,  in  presence  of  glucose,  yellow  cuprous  hy- 
droxide and  red  cuprous  oxide  are  precipitated  just  as  the  liquid 
begins  to  boil.  The  same  precipitation  occurs,  but  much  more 
slowly,  in  the  cold. 

7. — Fehling's  Test. — Heat  a  little  diluted  Fehling's  solution  (see 
Appendix)  to  boiling  in  a  test-tube,  and  add,  drop  by  drop,  the 
solution  to  be  tested.  The  presence  of  glucose  will  be  indicated 
by  the  production  of  a  yellowish-red  precipitate. 

Various  modifications  of  Fehling's  Test  have  been  proposed,  among  them  Pavy's 
and  Purdy's  Ammoniacal  Copper  Tests,  depending  upon  the  decolonization  of  the 
solution  instead  of  upon  the  production  of  the  red  precipitate,  Haine's  Test,  LoewJs 
Test,  Schmiedeberg' s  Test,  etc.  Formulae  for  Pavy's,  Purdy's  and  Haine's  solu- 
tions are  given  in  the  Appendix,  and  Purdy's  and  Haine's  tests  are  described  with 
the  tests  for  glucose  in  the  urine. 

8. — Indigo- Carmine  Test. — Add  sodium  carbonate  to  the  solution, 
to  render  it  alkaline,  and  then  add  sufficient  indigo-carmine  solu- 
tion to  impart  a  blue  color.  Boil,  and  the  solution  turns  first 


CARBOHYDRATES.  71 

violet,  then  yellow,  but  the  blue  color  may  be  restored  by  agitation 
with  air. 

9. — Phenylhydrazin  Test — Add  to  the  solution  two  grammes  of 
phenylhydrazin  hydrochloride,  and  four  grammes  of  sodium 
acetate.  Dissolve  the  salts  by  agitation  and  warm  on  the  water- 
bath  for  45  minutes.  If  glucose  be  present,  on  cooling,  if  not 
before,  a  yellow  crystalline  precipitate  of  glucosazone  will  separate 
out. 

10. — Alpha-naphthol  Test. — Add  to  the  liquid  a  saturated  solu- 
tion of  alpha-naphthol  and  an  excess  of  sulphuric  acid.  In  pres- 
ence of  glucose  (and  of  other  sugars)  a  violet  color  is  developed. 
The  addition  of  water  causes  a  blue  precipitate  to  form,  soluble  in 
alcohol,  ether,  and  sodium  hydroxide,  with  the  production  of  a 
yellow  solution. 

11. — Barfoed's  Test. — Boiled  with  Barfoed's  reagent  (see  Appen- 
dix) solutions  of  glucose  cause  a  precipitation  of  red  cuprous  oxide. 

For  the  detection  of  glucose  in  the  urine,  and  for  the  quantitative  esti- 
mation of  glucose,  see  under  Urine  Analysis. 

LEVULOSE  AND  GALACTOSE. 

Levulose  is  very  similar  to  dextrose,  differing  from  it  principally 
in  its  action  on  polarized  light,  being  Ia3vo-rotatory  while  dextrose 
is  dextro-rotatory.  It  is  less  easily  crystallized  and,  in  the  body, 
occurs  only  in  traces.  Chemical  tests  are  the  same  as  for  dextrose. 

Invert  Sugar  is  a  mixture  of  dextrose  and  levulose  obtained  by 
the  action  of  acids  and  of  certain  ferments  on  cane  sugar. 

Galactose  is  formed  by  the  action  of  acids  and  of  ferments  on  lac- 
tose. It  resembles  dextrose  closely. 

SUCROSE.     (Cane  Sugar. ) 

A  white  crystalline  solid,  easily  soluble  in  water,  insoluble  in 
absolute  alcohol  and  in  ether.  It  occurs  in  large  amount  in  sugar 
cane,  beet  root,  maple  sap,  etc. 

l._To  a  little  sugar  in  a  test-tube  add  sulphuric  acid  and  warm 
gently.  The  sugar  is  charred. 

2. — Heat  some  sugar  on  a  piece  of  platinum  foil.  It  melts, 
darkens,  chars,  and  burns,  giving  off  inflammable  gases  and  the 
characteristic  odor  of  caramel. 

3.  _To  a  solution  of  sugar  add  a  little  sodium  hydroxide  and 
warm.  If  the  sugar  be  pure  there  will  be  no  change  of  color. 
(Compare  with  Dextrose.) 


72  GARB  OHYDRA  TES. 

4. — Warmed  with  nitric  acid,  sugar  is  converted  into  saccharic, 
tartaric,  and,  finally,  oxalic  acid,  red  fumes  of  nitrogen  oxides 
being  evolved.  A  similar  reaction  is  given  with  other  carbohy- 
drates, and,  also,  with  arsenious  oxide. 

5. — Cane  sugar  does  not  reduce  Fehling's  Solution  ;  with  Trom- 
mer's  Test  a  blue  solution  is  obtained,  but  there  is  no  reduction, 
except  by  prolonged  boiling,  when  a  slight  precipitation  may  occur 
with  either  Fehling's  or  Trommer's. 

6. — By  the  action  of  yeast  and,  also,  by  boiling  with  dilute  acids, 
cane  sugar  is  converted  into  dextrose  and  levulose.  To  a  dilute 
solution  of  sugar,  add  a  little  hydrochloric  acid  and  boil  for  several 
minutes.  Cool  the  solution  and  apply  Trommer's  Test. 

Ci2H22011  4-H20  =  C6H1206  +  C6H1206. 

(Cane  Sugar.)  (Dextrose.)   (Levulose.) 

LACTOSE.     (Milk  Sugar.) 

A  white  crystalline  solid,  less  soluble  in  water  than  cane  sugar 
or  dextrose,  insoluble  in  alcohol  or  ether.  It  possesses  only  a  faint 
sweet  taste. 

Lactose  responds  to  most  of  the  tests  for  dextrose;  it  reduces 
Fehling's  solution,  though  less  strongly  than  dextrose,  and  answers 
to  Trommer's  test.  It  differs  from  dextrose  in  not  directly  under- 
going alcoholic  fermentation  with  yeast  (commercial  samples  often 
ferment  rapidly),  and  by  giving  negative  results  with  Barfoed's 
test.  In  the  phenylhydrazin  test  the  crystals  obtained  are  larger 
than  with  dextrose.  By  the  lactic  acid  micro-organism,  as  in  the 
ordinary  souring  of  milk,  lactose  is  converted  first  into  lactic  acid 
and  then  into  butyric  acid,  but  by  certain  other  ferments,  and  by 
boiling  with  acids,  it  is  changed  into  galactose  which  may  then 
undergo  ordinary  alcoholic  fermentation.  The  freedom  of  lactose 
from  cane  sugar  may  be  tested  by  sprinkling  it  on  strong  sulphuric 
acid  ;  after  one-half  hour  there  should  be  no  brown  coloration. 
Lactose  may  be  separated  from  milk  by  acidulating  with  dilute 
acetic  acid,  filtering  off  the  coagulated  caseinogen  and  evaporating 
the  filtrate. 

MALTOSE. 

A  white,  crystalline  substance,  needle-shaped  crystals,  soluble 
in  both  water  and  alcohol,  produced  by  the  action  of  diastatic  fer- 
ments on  starch.  Like  lactose  it  responds  to  nearly  all  of  the 


CARBOHYDRATES.  73 

glucose  tests.  Its  reducing  power  with  Fehling's  Solution  is  one- 
third  less  than  that  of  glucose,  while  its  dextro-rotation  of  polar- 
ized light  is  more  than  twice  as  great.  It  readily  undergoes  alco- 
holic fermentation,  and  by  prolonged  boiling  with  water,  or  more 
easily  by  boiling  with  dilute  acids,  it  is  converted  into  dextrose. 

Maltose  resembles  lactose  but  may  be  differentiated  by  means 
of  the  fermentation  test.  It  differs  from  glucose,  in  giving  a  nega- 
tive result  when  boiled  with  Barfoed's  reagent. 

CELLULOSE. 

Prepared  by  reducing  vegetable  tissues  to  a  pulp  and  washing 
out  the  starches,  gums,  salts.,  etc.,  present. 

Cotton-wool,  which  is  nearly  pure  cellulose,  is  suitable  for  most 
of  the  tests. 

1. — To  some  cotton  in  a  test-tube  add  a  little  sodium  hydroxide. 
Warm  the  mixture  and  let  it  stand.  Note  that  the  fibres  swell 
slightly  and  become  more  or  less  gelatinous. 

2. — To  a  second  sample  add  strong  sulphuric  acid  and  warm 
gently.  Note  that  the  cotton  turns  brown  or  black,  and  goes  par- 
tially or  entirely  into  solution. 

3. — Dissolve  some  pure  cellulose  in  a  solution  of  ammonio- 
cupric  hydroxide.  Then  add  hydrochloric  acid  carefully  until  the 
blue  color  of  the  solution  is  destroyed,  and  note  that  the  cellulose 
is  precipitated  in  a  stringy  mass. 

4. — Cellulose  is  insoluble  in  water,  alcohol,  or  ether. 

5. — By  treatment  with  mineral  acids  cellulose  can  be  partially 
converted  into  dextrose. 

Cellulose  treated  with  a  mixture  of  nitric  and  sulphuric  acids  yields  tetra-  and 
penta-nitrates  (pyroxylin]  which  dissolve  in  a  mixture  of  ether  and  alcohol  to  form 
collodion.  Longer  treatment  with  the  acids  yields  a  hexa-nitrate,  gun  cotton, 
(C6H7O2)2(NO3)6,  insoluble  in  ether  and  alcohol.  Celluloid  is  a  solution  of  pyroxy- 
lin in  camphor. 

STARCH. 

A  white,  inodorous,  tasteless  substance,  insoluble  in  ether,  alco- 
hol, or  cold  water.  Under  the  microscope  it  appears  in  uniform 
granules  of  characteristic  appearance. 

1. — Add  a  few  grains  of  starch  to  a  little  sodium  hydroxide  in  a 
test-tube.  Note  that  the  starch  swells  and  forms  a  thick  paste  in 
the  cold. 

2. — Prepare  some  starch  paste  as  follows:  Add  sufficient  ground 


74  CARBOHYDRATES. 

starch  to  water  in  a  test-tube  to  form  a  milky  fluid.  Pour  this 
milky  fluid  into  a  beaker  of  boiling  water.  Note  that  the  milky 
appearance  disappears.  Dilute  some  of  the  "paste"  so  formed, 
in  another  beaker  with  water.  When  cool,  add  a  few  drops  of 
iodine  solution.  A  blue  color  is  produced.  Divide  this  blue 
solution  into  three  parts,  (a)  Heat  one  part  carefully  until  the 
color  disappears.  Upon  cooling,  the  color  will  again  develop.  If 
carefully  performed  this  may  be  repeated  several  times.  (6)  To 
the  second  part,  add  a  few  drops  of  sodium  hydroxide.  The  blue 
color  is  destroyed,  but  may  be  reproduced  by  the  addition  of  dilute 
h}^drochloric  acid,  (c)  To  the  third  part,  add  mercuric  chloride. 
The  blue  color  is  destroyed. 

3.  —  Starch  is  insoluble  in   cold   water,    or  in  alcohol.     When 
heated  with  water  it  is  partially  dissolved,  the  soluble  portion  be- 
ing known  as  granulose,  the  insoluble  portion,  as  starch-cellulose. 
To  some  of  the  clear  starch  solution  obtained  in  (2)  add  alcohol. 
The  granulose  is  precipitated. 

4.  —  To  some  of  the  solution  obtained  in  (2)  add  dilute  hydro- 
chloric acid  and  heat  to  boiling.     Test  a  small  portion  of  the  solu- 
tion in  another  test-tube,  with  iodine.     If  the  boiling  has  been 
sufficient  no  color  will  appear,    showing  the  conversion  of   the 
starch  into  dextrose  and  dextrin. 

2(C6H1005)+H20  =  C6H1206+C6H1005. 

The  dextrin  first  produced  gives  a  red  or  brown  coloration  with 
the  iodine. 

5.  —  By  the  action  of  diastatic  ferments  starch  is  converted  into 
maltose  and  dextrin. 


Mix  a  little  of  the  diluted  starch  paste,  prepared  in  2,  with 
saliva,  and  warm  to  about  the  temperature  of  the  body.  At  inter- 
vals test  a  drop  of  the  mixture  with  a  drop  of  iodine  solution  on  a 
porcelain  plate.  The  blue  color  first  obtained,  indicating  starch, 
will  gradually  give  place  to  a  brownish-red  color  due  to  erythro- 
dextrin.  No  color  with  the  iodine  shows  conversion  of  the  starch 
into  achroo-dextrin.  The  presence  of  maltose  may  be  proved  by 
Fehling's  test,  q.  v.,  both  starch  and  dextrin  being  non-reducing. 

DEXTRIN. 
An  amorphous  substance,  readily  soluble  in  water,  insoluble  in 


CARBOHYDRATES.  75 

alcohol  and  in  ether,  produced  by  hydrolysis  of  starch  and  other 
amyloses.  There  are  two  varieties,  ery thro- dextrin  which  gives  the 
iodine  test  below,  and  achroo-dextrin  which  does  not  give  the 
iodine  test.  Pure  dextrin  is  non-reducing,  arid  does  not  undergo 
fermentation  with  yeast. 

1. — Drop  some  of  the  aqueous  solution  into  alcohol;  a  white 
precipitate  is  formed. 

2. — A  drop  of  iodine  solution  added  to  a  solution  of  dextrin 
gives  a  reddish-brown  coloration  which  disappears  when  the  solu- 
tion is  heated,  but  reappears  on  cooling. 

3.  —Basic  lead  acetate  gives  no  precipitate.      (Unlike  glycogen.) 

4. — Boiling  with  dilute  hydrochloric  acid  converts  dextrin  into 
dextrose. 

GLYCOGEN. 

A  white  or  yellowish-white  tasteless  amorphous  powder,  insolu- 
ble in  alcohol  or  ether,  imperfectly  soluble  in  boiling  water.  It  is 
present  in  the  tissues  of  the  body,  abundantly  in  embryonic  tissue. 

1. — With  iodine,  glycogen  gives  a  deep  red  color  when  in  sohi- 
tion,  a  brown  color  when  in  form  of  powder.  On  heating  the 
solution  the  color  disappears,  but  reappears  on  cooling. 

2. — With  sodium  hydroxide  and  one  or  two  drops  of  copper 
sulphate  a  blue  coloration  is  obtained,  but  there  is  no  precipitate 
on  boiling.  (See  Trommer's  Test,  under  Dextrose.) 

3. — Basic  lead  acetate  precipitates  glycogen  from  its  aqueous 
solution,  (Unlike  dextrin.) 

4.— Boiling  with  dilute  hydrochloric  acid  converts  glycogen  into 
dextrose. 


THE  PROTEIDS. 


THE  proteids  occur  in  both  the  vegetable  and  animal  kingdoms, 
most  abundantly  in  the  latter.  They  all  contain  carbon,  hydro- 
gen, oxygen  and  nitrogen;  most  of  them  contain  sulphur,  and 
phosphorus  is  present  in  a  few.  Various  formula  have  been  cal- 
culated for  the  simpler  proteids,  but  little,  however,  is  known  re- 
garding their  true  constitution.  They  vary  in  composition  as  fol- 
lows (Hoppe-Seyler): 

C  H  N  S  0 

From     51.5         6.9         15.2        0.3         20.9 
To         54.5        7.3        17.0        2.0        23.5 
On  decomposition  the  proteids  yield  ammonium  compounds, 
amines,  fatty  acids  amido-acids,  aromatic  compounds,  etc. 
Classification  : 

A.  SIMPLE  PROTEIN  SUBSTANCES. 

I.  FUNDAMENTAL.  Albumins.  I.  Egg-Albumin.  2.  Serum- 
Albumin.  3.  Cell-Albumin.  4.  Muscle-Albumin.  5. 
Lact- Albumin. 

Globulins.      1.    Serum-Globulin.      2.    Cell-Globulin. 
3.   Fibrinogen.     4.   Myosinogen. 

II.   DERIVED.     1.   By  action  of  acids  or  alkalies,  Acid- Albumin 
and  Alkali- Albumin.     2.   By  ferments,  Fibrin,  Myosin. 
3.   By  ferments  plus  acids  or  alkalies,   Proteoses  (Albu 
moses),   Peptones.     4.   By  heat,  Coagulated  Albumins 
and  Coagulated  Globulins. 

B.  COMPLEX  PROTEIN  SUBSTANCES.     (The  "Proteids"  of  Ger- 

man authors. ) 

Mucin  ;     Nucleo-Albumins,     Caseinogen,     Vitellin,    and 
Thrombin;  Hemoglobin. 

C.  ALBUMINOID  OR  GELATINOID  SUBSTANCES. 

Collagen,  Ossein  and  Gelatin;  Chondrigen  and  Chondrin; 
Elastin;  Eleidin  and  Keratin;  Lardacein,  etc. 
(76) 


PROTEIDS.  77 

TESTS  FOR  THE  PROTEIDS. 

All  proteids  are  insoluble  in  alcohol.  Some  are  soluble  in 
water,  others  are  not.  Many  not  soluble  in  water  are  soluble  in 
dilute  saline  solutions.  Some  are  soluble  in  concentrated  saline 
solutions,  others  are  insoluble.  All  are  soluble  when  heated  with 
strong  acids,  and  all  are  soluble,  after  change,  in  the  gastric  and 
pancreatic  juices.  The  classification  and  subdivision  of  the  pro- 
teids depend  upon  their  behavior  with  the  above  reagents. 

'  The   Protein    Reactions"     (Applying    to    nearly    all    protein 
bodies). 

1. — Xantho-proteic  Reaction. — To  a  little  of  the  solution  in  a  test- 
tube,  add  a  few  drops  of  cone,  nitric  acid  and  heat  to  boiling.  A 
yellow  color  is  produced.  Cool,  and  render  the  solution  alkaline 
with  sodium  hydroxide.  An  orange-yellow  color  is  obtained. 

2. — Millon's  Reaction. — To  the  solution  add  a  few  drops  of 
Millon's  Reagent  (See  Appendix)  and  boil.  The  white  precipi- 
tate first  formed  turns  red  on  heating.  The  presence  of  sodium 
chloride  interferes  with  this  reaction. 

3. — Biuret  Reaction.  (Piotrowski's. ) — Render  the  solution  alka- 
line with  sodium  hydroxide  and  add  one  or  two  drops  of  dilute 
copper  sulphate;  a  violet  coloration  is  obtained.  With  peptones, 
however,  the  color  obtained  is  rose-red. 

REMOVAL  OF  PROTEIDS  FROM  SOLUTIONS. 

It  is  frequently  necessary  to  remove  the  proteids  from  a  solution 
preparatory  to  tests  for  other  substances.  In  urine  analysis,  for 
instance,  the  albumin  must  be  removed  before  testing  for  sugar, 
or  for  urea.  This  removal  may  be  accomplished,  in  most  cases, 
by  heating  to  boiling  the  slightly  acid  solution.  Albumins  and 
Globulins  are  coagulated  and  may  be  filtered  off.  If  the  solution 
is  not  already  acid,  render  so  by  addition  of  acetic  acid.  The 
same  result  may  be  obtained  by  the  addition  of  an  excess  of  abso- 
lute alcohol  to  the  slightly  acid  solution,  all  proteids  being  thereby 
precipitated.  A  third  method,  of  wide  application,  is  the  follow- 
ing: Add  to  the  solution  a  few  drops  of  acetic  acid  (sufficient  to 
acidulate  it),  then  saturate  with  crystals  of  ammonium  sulphate. 
Boil  for  several  minutes  and  filter.  Saturation  with  ammonium 
sulphate  precipitates  all  proteids  except  peptones. 


78  QUALITATIVE  ANALYSIS. 

ALBUMINS. 

Albumins  are  soluble  in  water,  in  dilute  saline  solutions,  and  in 
saturated  solutions  of  sodium  chloride,  and  magnesium  sulphate. 
They  are  coagulated  by  heat,  egg-albumin  at  about  73°  0.,  and 
are  precipitated  by  saturation  with  ammonium  sulphate. 

1. — Mercuric  chloride  precipitates  white  albuminate  of  mercury. 

2. — Copper  sulphate  precipitates  blue  albuminate  of  copper. 

3. — Add  to  the  solution  a  few  drops  of  acetic  acid  and  then  a 
little  potassium  ferrocyanide.  A  precipitate  is  formed. 

4. — Picric  Acid  Test. — Add  to  the  solution  a  few  drops  of  picric 
acid;  a  precipitate  is  formed. 

5. — Tannic  Acid  Test. — Add  to  the  solution  a  few  drops  of  a 
solution  of  tannin.  A  precipitate  is  formed. 

6. — Nitric  Acid  forms  a  white  precipitate  if  not  added  in  excess. 

7. — Nitric  Acid  Contact  Test. — Place  about  one  inch  of  strong 
nitric  acid  in  a  test-tube,  and  float  over  it  carefully,  so  as  to  avoid 
admixture,  some  of  the  solution  to  be  tested.  In  the  presence  of 
albumin,  a  white  cloudy  ring,  or  zone,  will  form  at  the  contact  of 
the  two  liquids. 

.i  — Acidulated  Brine  Test. — Place  the  acidulated  brine  (see  Ap- 
»  jndix)  in  a  test-tube,  and  float  over  it  the  solution  to  be  tested. 

white  precipitate  is  formed  at  the  juncture  of  the  two  liquids. 

9. —  Tanrefs  Test. — Place  the  Tan  ret' s  Solution  (see  Appendix) 
in  a  test-tube,  and  float  over  it  the  solution  to  be  tested.  A  white 
precipitate  is  formed  at  the  juncture  of  the  two  liquids. 

10. — Trichloracetic  Acid  Test. — Add  some  of  the  crystals  to  the 
solution  to  be  tested,  and  allow7  them  to  dissolve  without  agitation 
at  the  bottom  of  the  tube.  A  white  precipitate  is  formed. 

11. — Heat  Test. — Heat  some  of  the  aqueous  solution  of  albumin 
just  to  boiling.  The  albumin  is  coagulated,  forming  a  white  pre- 
cipitate. The  solution  should  be  slightly  acid.  The  temperature 
at  which  the  coagulation  takes  place  averages  between  60°  C.  and 
75°  C. 

12. — Burn  a  small  fragment  of  solid  albumin  on  a  piece  of  plat- 
inum foil.  Note  the  characteristic  odor  of  burnt  horn. 

Egg-  and  Serum-Albumin  may  be  readily  distinguished  by  the 
following  tests  : 


I 


PROTEIDS. 


79 


Egg-Albumin. 

1. — Rapidly  precipitated  by  al- 
cohol. 

2. —  Precipitated  by  ether. 

3.— Readily  precipitated  by 
HC1,  the  precipitate  not 
dissolving  in  excess. 


Serum-  A  Ibumin. 

1. — Slowly  precipitated  by  al- 
cohol. 

2. — Not  precipitated  by  ether. 

3. — Not  readily  precipitated  by 
HC1,  the  precipitate  dis- 
solving easily  in  excess. 


For  the  detection  of  Albumin  in  the  Urine,  see  under  Urine  Analysis. 
TESTS  FOR  SULPHUR  IN  ALBUMIN. 

1- — Heat  a  solution  of  lead  acetate  in  a  test-tube  and  add  sodium 
hydroxide  until  the  white  precipitate  of  lead  hydroxide,  first 
formed,  is  just  redissolved.  Boil  the  clear  liquid,  and  while  boil- 
ing add  a  little  albumin  solution.  The  mixture  turns. brownish- 
black  from  the  formation  of  lead  sulphide. 

2. — Heat  a  little  of  the  solid  albumin  in  a  tube,  and  hold  in  the 
mouth  of  the  tube  a  piece  of  paper  moistened  with  lead  acetate. 
The  paper  is  blackened  by  the  fumes  evolved. 

3. — Boil  some  albumin  solution  with  a  few  grains  of  bismuth 
subnitrate  and  an  excess  of  sodium  hydroxide.  A  brownish-black 
precipitate  of  sulphide  of  bismuth  is  formed. 

GLOBULINS. 

The  globulins  resemble  the  albumins  in  being  soluble  in  dilute 
saline  solutions,  in  being  coagulated  by  heat,  and  in  being  precipi- 
tated by  ammonium  sulphate.  In  the  latter  case,  however,  half 
saturation  (add  equal  volume  of  saturated  ammonium  sulphate 
solution)  suffices  to  precipitate  globulins,  while  for  the  precipita- 
tion of  albumins  full  saturation  with  crystals  of  ammonium  sul- 
phate is  required.  Unlike  the  albumins,  they  are  insoluble  in 
pure  water  and  insoluble  in  concentrated  solutions  of  sodium 
chloride,  or  of  magnesium  sulphate. 

Serum- Globulin,  also  known  as  fibrinoplastin  and  paraglobulin, 
is  the  principal  globulin  of  the  blood.  Fibrinogen  is  that  substance 
which,  under  the  influence  of  a  ferment,  gives  rise  to  the  fibrin  of 
clotted  blood. 

ACID-  AND  ALKALI-ALBUMINS. 

Acid-  and  alkali-albumins,  the  so-called  albuminates,  are  de- 
rived from  albumins  and  globulins  by  the  action  of  weak  acids  and 


80  Q  UALITA  TIVE  ANAL  YSIS. 

alkalies.  They  are  soluble  in  acids  and  alkalies,  and  in  dilute 
saline  solutions,  but  are  precipitated  by  saturation  with  neutral 
salts.  They  are  not  coagulated  by  heat. 

1. — To  the  albuminous  fluid  add  a  considerable  amount  of 
acetic  acid.  An  acid-albumin  is  formed.  Boil,  and  note  that  there 
is  no  coagulation. 

(a)  Apply  the  xantho-proteic  reaction  to  part  of  the  solution 
obtained  in  1.  v 

(b)  Add  carefully,  to  another  part  of  the  same  solution,  dilute 
sodium  hydroxide,  and  note  that  when  the  acid  is  just  neutralized 
the  albumin  will  be  precipitated. 

2. — To  the  albuminous  fluid  add  a  few  drops  of  sodium  hydrox- 
ide and  warm  the  mixture.  An  alkali-albumin  is  formed.  Boil 
the  solution  and  note  that  there  is  no  coagulation. 

(a)  Apply  the  biuret  test  to  part  of  the  solution  obtained  in  2. 

(b)  Add  carefully,  to  another  part  of  the  same  solution,  acetic 
acid,  and  note  that  when  the  sodium  hydroxide  is  just  neutralized 
the  albumin  will  be  precipitated. 

PROTEOSES  AND  PEPTONES. 

The  Proteoses  are  intermediate  products  in  the  digestion  of  pro- 
teids.  They  are  not  coagulated  by  heat.  They  are  precipitated, 
but  not  coagulated,  by  alcohol.  With  nitric  acid  a  precipitate  is 
obtained  which  disappears  on  heating  and  reappears  on  cooling. 
With  the  biuret  test  proteoses  behave  much  like  peptones. 

The  Peptones  are  final  products  in  the  digestion  of  proteids. 
They  are  easily  soluble  in  water  and  are  not  precipitated  by  heat, 
by  nitric  acid,  or  by  ammonium  sulphate. 

Test  a  solution  of  a  peptone  as  follows: 

1. — Apply  the  Xantho-Proteic  test.  The  characteristic  colora- 
tion is  obtained.  '^vlDj 

2. — Apply  the  Biuret  test,  taking  care  to  use  but  a  trace  of  cop- 
per sulphate.  With  a  larger  amount  of  copper  salt  the  color  ob- 
tained will  be  a  purple-red,  not  unlike  that  given  by  other  proteids. 

3. — Mercuric  chloride  precipitates  a  white  peptonate. 

4. — Picric  acid  precipitates  a  yellowish-white  picrate  of  peptone. 

5. — Nitric  acid,  acetic  acid  and  potassium  ferrocyanide,  and 
copper  sulphate,  give  no  precipitates  with  peptones.  Note,  also, 
that  tests  3  and  4  are  not  obtained  with  dilute  solutions. 


PROTEIDS.  81 

COAGULATED  PROTEIDS. 

Proteids  coagulated  by  heat  are  insoluble  in  water,  in  weak 
acids  or  alkalies.  They  are  soluble,  after  long  boiling,  with  strong 
mineral  acids,  and  in  the  gastric  and  pancreatic  juices.  Coagulate 
some  egg-albumin  by  heat  and  test  the  coagulum  according  to  the 
Xantho-Proteic,  the  Millon's,  and  the  Biuret  tests,  all  of  which 
should  give  positive  results. 

COMPLEX  PROTEIN  SUBSTANCES. 

Under  this  classification  are  included  a  number  of  compound 
bodies,  compounds  of  an  albumin  or  globulin  with  a  radical 
foreign  to  the  protein  nature.  The  principal  recognized  members 
of  the  class  are  as  follows:  Mucin  and  Metalbumin,  compounds  of 
albumin  or  globulin  with  a  carbohydrate  radical;  Nucleo- Albumins, 
including  Caseinogen,  Vitellin  and  Thrombin,  phosphorus-holding 
compounds  of  albumin  or  globulin  with  a  nuclein  radical;  Haemo- 
globin, a  compound  of  a  globulin  with  an  iron-holding  radical. 

Caseinogen  was  formerly  classed  as  an  alkali-albumin,  and 
Vitellin  as  a  typical  globulin. 

THE  ALBUMINOIDS  OR  GELATINOIDS. 

As  important  members  of  this  class  we  have,  Collagen,  from  the 
white  connective  tissue;  Ossein,  a  collagen  from  the  bones;  Gela- 
tin, derived  from  collagen  by  boiling  with  water;  Chondrin,  similar 
to  gelatin,  derived  from  the  Chondrigen  of  the  cartilages;  Elastin, 
Eleidin,  Keratin,  Lardacein  or  Amyloid  Substance,  etc. 

GELATIN. 

When  dried  and  pulverized  bones  are  digested  with  dilute 
hydrochloric  acid,  the  mineral  salts  are  dissolved  and  ossein  left 
behind.  This  last  heated  with  water  is  rapidly  converted  into  the 
substance  gelatin.  Test  the  properties  of  gelatin  as  follows: 

1.— Try  the  action  of  cold  water.  The  gelatin  swells  without 
dissolving. 

2. — Warm  the  mixture  and  it  will  be  found  that  the  gelatin 
dissolves.  Divide  this  solution  into  two  parts: 

(a)  Allow  one  part  to  cool  in  a  test-tube,  and  note  that  on  cool- 
ing the  gelatin  separates  out,  or  "gelatinizes." 

(6)  Boil  the  remainder  of  the  solution  for  several  minutes,  and 
then  let  it  cool.  Note  that  now  it  does  not  gelatinize. 


82  PROTEIDS. 

3. — To  the  solution  obtained  in  2,  b,  or  to  a  fresh  solution  of 
gelatin,  apply  the  following  tests: 

(a)  The  Xantho-proteic  test  gives  a  lemon-yellow  color. 

(6)  The  Biuret  test  gives  the  usual  violet  color. 

(c)  Millon's  test  is  negative  in  result  with  pure  gelatin. 

(d~)  Mercuric  chloride  and  picric  acid  give  precipitates  from 
strong  solutions. 

(e~)  Nitric  acid  gives  no  precipitate. 

In  dilute  solution  gelatin  resembles  peptone.  The  following 
tests  will  serve  to  distinguish  between  the  two: 

Peptones.  Gelatin. 

1.  Feeble  osmotic  power.  1.   No  osmotic  power. 

2.  Alcohol   precipitates    with        2.  Alcohol  precipitates  easily. 

difficulty. 

3.  Saturation  with  ammonium        3.   Saturation  with  ammonium 

sulphate  causes  no  pre-  sulphate  causes  a  precip- 

cipitate.  itate. 

4.  Solutions  do  not  gelatinize.        4.   Solutions  gelatinize. 

SEPARATION  AND  IDENTIFICATION  OF  THE  CHIEF  PROTEIN  CLASSES. 

1.  If  the  proteid  be  solid,  test  its  solubility.     1. — Soluble  in  pure 
water. 

(a)  Coagulated  by  heat,  Albumins. 

(b)  Not  coagulated  by  heat,  Peptones. 

2.  Insoluble  in  pure  water,  soluble  in  one  per  cent,  solution  of 
sodium  chloride,  Globulins,  Vitellin  and  Crystallin. 

(a)  Precipitated  by  saturation  with  sodium  chloride,  Vitellin, 
Crystallin. 

3.  Insoluble  in  pure  water  or  dilute  sodium  chloride,  but  solu- 
ble in  acids  and  in  the  gastric  juice. 

(a)  Soluble  in   dilute  hydrochloric  acid  or  in   dilute  alkalies, 
Albuminates. 

(b)  Insoluble  in  dilute  acids  and  alkalies,   but   easily  soluble 
when  digested  with  gastric  and  pancreatic  juice,   Coagulated  Pro- 
teids. 

(c)  Insoluble  in  water,  sodium  chloride,  dilute  acids,  or  gastric 
juice,  soluble  in  the  stronger  alkalies  and  in  strong  hydrochloric 
acid.     Lardacein  (Amyloid  Substance). 


PROTEWS.  83 

II.  If  the  proteid  be  in  solution,  (1)  Test  a  portion  of  the  solution 
for  proteids  by  the  Xantho-proteic,  Millon's  and  Biuret  Tests. 

2. — Test  the  reaction  of  the  solution. 

(a)  If  acid,  apply  tests  for  the  acid-albuminates. 

(6)  If  alkaline,  test  for  the  alkali- albuminates. 

3. — Acidify,  if  necessary,  and  boil  the  solution.  If  there  be  a 
coagulation  the  proteid  is  either  an  albumin,  or  a  globulin.  Sat- 
urate some  of  the  original  solution  with  magnesium  sulphate.  A 
precipitate  indicates  Globulin ;  if  no  precipitate  be  formed,  Albumin 
is  present. 

4. — If  the  proteid  is  not  coagulated  by  heat,  it  is  then  probably 
either  an  albuminate,  an  albumose,  or  a  peptone. 

(a)  Albuminates  were  tested  for  under  II.  2,  a,  b. 

(6)  An  Albumose  would  be  recognized  by  the  biuret  reaction  (sim- 
ilar to  that  given  for  peptones)  and  by  the  characteristic  reaction 
with  nitric  acid.  Albumose  is  precipitated  by  nitric  acid  in  the 
cold,  the  precipitate  dissolves  on  heating,  and  reappears  when  the 
liquid  cools. 

(c)  Peptones  may  be  recognized  by  the  biuret  reaction,  by  giv- 
ing no  precipitate  with  nitric  acid,  and  no  precipitate  on  saturation 
with  ammonium  sulphate. 


THE  FATS  AND  OILS. 


The  fat  of  adipose  tissue  is  a  mixture  of  the  glycerides  of  pal- 
mitic, stearic  and  oleic  acids,  the  trivalent  glyceryl  radical  uniting 
with  three  univalent  acid  radicals,  thus: — glycerol,  C3H5(OH)3; 
glycerjd,  (C3H5)m;  palmitic  acid,  HC16H3102;  palmitin,  the 
fat  =  C3H5  (Cj  6H3  !02 )  3.  In  the  same  way  are  formed  the  glycer- 
ides of  stearic  acid,  HC18H3502,  and  oleic  acid,  HC18H3302. 
Butter  fat  contains,  in  addition,  glycerides  of  butyric  acid  (C4), 
caproic  acid  (C6),  caprylic  acid  (C8),  capric  acid  (C10),  lauric 
acid  (C12),  and  myristic  acid  (C14),  all  acids  of  the  series 
HCnH2n_102.  Olein  is  a  liquid  fat,  palmitin  and  stearin  are  solid, 
stearin  having  the  higher  melting-point.  The  greater  the  propor- 
tion of  olein  present  the  more  liquid  will  be  the  fat;  the  greater  the 
proportion  of  stearin  the  more  solid  the  fat.  In  the  adult  human 
body  the  fats  are  fluid  during  life,  the  body  temperature  being 
37°  C.  and  the  mixture  of  fats  present  melting  at  about  26°  C. 
The  fats  are  soluble  in  hot  alcohol,  in  ether  and  in  chloroform; 
they  are  insoluble  in  water. 

Test  of  Melting  Point. — Heat  some  beef-fat  in  a  dry  dish,  avoid- 
ing too  high  a  temperature,  and  filter  the  melted  fat  obtained 
through  dry  filter  paper.  A  one-fourth  inch  glass  tube  is  closed 
at  one  end  by  fusion  and  the  cooled,  solid,  fat  introduced.  The 
tube  is  then  fastened  to  the  bulb  of  a  thermometer  and  suspended 
with  it  in  a  beaker  of  water,  care  being  taken  that  no  water  enters 
the  tube.  The  temperature  of  the  water  is  gradually  raised  and 
the  temperature  at  which  the  fat  softens  is  noted.  This  will  be 
between  40°  and  50°  C. 

The  fats  vary  in  specific  gravity  from  0.91  to  0.97.  They  are 
insoluble  in  water  and,  generally,  in  cold  alcohol,  but  are  soluble 
in  boiling  alcohol,  in  chloroform,  and,  generally,  in  benzine  and 
other  petroleum  products.  Strongly  heated  they  yield  pungent, 
irritating  fumes  of  acrolein.  Decomposition  of  fat  by  putrefactive 

(84) 


FATS  AND  OILS.  85 

organisms  results  in  the  formation  of  propionic,  acetic  and  formic 
acids  —  the  fat  becomes  rancid. 

Decomposed  by  ferments,  by  superheated  steam,  or  by  an  alkali 
or  metallic  oxide,  the  fat  yields  glycerol  and  either  the  free  fatty 
acid  or  a  metallic  salt  of  that  acid  known  as  a  soap.  The  "  sapon- 
ification"  of  a  fat  with  formation  of  a  "soft"  potash  soap  may 
be  indicated  as  follows: 


=  3KC1.H,t01+CtH.(OH)t. 

Olein.  Potassium  oleate.  Glycerol. 

The  ordinary  soaps  are  soluble  in  water,  but  when  added  in  ex- 
cess the  solution  becomes  turbid  from  a  partial  decomposition,  free 
alkali  and  an  insoluble  acid  salt  being  liberated.     By  addition  of 
mineral  acids  the  soap  is  decomposed  and  the  fatty  acid  set  free. 
KC18H3302+HC1  =  KC18H3302-HKC1. 

By  addition  of  sodium  chloride  a  "soft"  potash  soap  may  be 
transformed  into  a  "  hard  "  soda  soap. 

KC18H8802+NaCl  =  NaC18H8802+KCl. 

By  the  addition  of  other  metallic  salts  the  soda  soap  may  be 
further  transformed. 

Saponification  and  Soap  Tests.  —  Warm  10  c.c.  of  castor  oil  (or  of 
olive  oil)  in  a  porcelain  dish,  and  add  slowly,  with  constant  stir- 
ring, 10  c.c.  of  10  per  cent,  sodium  hydroxide  solution.  Continue 
the  heating  and  stirring  until  the  mass  begins  to  thicken,  then  set 
aside  to  cool. 

In  making  the  test  on  so  small  a  scale,  the  hard  white  soap 
obtained  with  castor  oil  is  generally  more  satisfactory  than  the 
flaky  "Castile  Soap"  (Sapo  U.  S.  P.)  obtained  with  olive  oil. 

Dissolve  some  of  the  soap  in  hot  water  and  place  in  6  test-tubes. 
1.  —  Note  the  lather  produced  on  shaking.  2.  —  Add  CaCl2,  and 
note  that  no  lather  is  produced  on  shaking,  but  that  an  insoluble 
lime  soap  is  precipitated.  3,  4  and  5.  —  Add,  respectively,  Fe2Cl6, 
CuSO4,  and  Pb(C2H302)2.  Note  the  formation  of  iron,  copper 
and  lead  soaps.  6.  —  Add  a  few  drops  of  cone,  hydrochloric  acid 
and  note  the  separation  of  the  fatty  acids.  Warm,  and  the  acids 
rise  to  the  top  of  the  liquid  like  oil. 

Soft  Soap,  Sapo  Mollis,  U.  S.  P.—  Heat  400  grammes  of  linseed  oil 
to  60°  C.,  and  add  slowly  while  stirring  a  solution  of  potassium 
hydroxide  (90  grammes,  in  water,  450  c.c.,  and  alcohol,  30  c.c.). 
Continue  the  heating  and  stirring  until  a  portion  of  the  soft  mass 


86  FATS  AND  OILS. 

will  dissolve  in  boiling  water  without  separation  of  oily  drops. 
The  test  may  be  satisfactorily  made  on  the  small  scale,  using  pro- 
portionate amounts  of  oil  and  alkali. 

Lead  Plaster •,  Emplastrum  Plumbi,  U.  S.  P. — Mix  320  grammes  of 
lead  oxide  (litharge)  with  300  grammes  of  olive  oil  by  trituration, 
and  add  the  mixture  to  another  300  grammes  of  the  oil  in  a 
capacious  vessel.  Then  add  100  c.c.  of  boiling  water,  and  boil, 
with  constant  stirring,  until  a  portion  dropped  in  cold  water  be- 
comes pliable  and  tenacious.  The  water  lost  by  evaporation  must 
be  replaced  from  time  to  time.  .  When  the  whole  is  whitish  and 
homogeneous,  transfer  to  a  vessel  containing  warm  water  and  knead 
out  the  glycerin,  renewing  the  water  as  necessary.  The  "plaster" 
consists  essentially  of  lead  oleate,  Pb(C18H33O2)2'  The  test  may 
be  satisfactorily  made  on  a  smaller  scale  using  proportionate 
amounts  of  lead  oxide  and  of  oil. 

THE  OILS  differ  from  the  solid  fats  in  their  greater  proportion  of 
olein  and  of  other  fats  with  low  melting-points,  and  in  their  con- 
sequent fluidity  at  ordinary  temperatures.  As  examples  of  the 
oils  may  be  mentioned: 

Castor  Oil,  a  mixture  of  olein  and  ricinolein,  €3115(0!  8H3303)3, 
with  palmitin,  etc.  It  is  an  almost  colorless,  viscid  liquid,  soluble 
in  alcohol  and  in  an  equal  volume,  but  not  in  an  excess,  of  ben- 
zine. A  drop  of  cone,  sulphuric  acid  added  to  a  few  drops  of  the 
oil  spread  upon  porcelain  produces  a  brown  coloration  with  a 
yellow  margin. 

Olive  Oil  consists  chiefly  of  olein  writh  palmitin,  arachidin, 
cholesterol,  and  some  albuminous  matter.  It  is  a  pale  greenish- 
yellow  liquid  with  characteristic  odor,  sparingly  soluble  in  alcohol, 
readily  soluble  in  benzine,  ether  and  chloroform.  With  sulphuric 
acid  (see  under  castor  oil)  the  coloration  produced  has  a  brownish 
center  and  an  olive-green  margin. 

Cod  Liver  Oil  is  a  mixture  of  olein  with  palmitin,  myristin,  and 
other  more  obscure  compounds.  It  is  a  pale  yellow,  thin,  oily 
liquid,  easily  soluble  in  benzine,  ether,  and  chloroform,  but  nearly 
insoluble  in  alcohol.  WMth  sulphuric  acid  (see  under  castor  oil) 
the  coloration  produced  has  a  reddish-brown  center  and  more  or 
less  of  a  purple  margin. 

LECITHIN,  a  complex  fat  containing  phosphorus,  is  found  in 
nerve  tissue,  in  cell  protoplasm,  in  the  bile,  blood,  etc.  On  decom- 
position it  yields  glycerol,  stearic  acid,  choline,  and  phosphoric  acid. 


FERMENTS  AND  FERMEN- 
TATION. 


The  ferments  are  divided  into  two  classes,  the  Organized  and 
the  Unorganized. 

The  Organized  ferments  are  living  cells,  the  multiplication  of 
which  is  accompanied  by  changes  in  the  tissues  upon  which  they 
feed.  In  this  chemical  metamorphosis  complex  compounds  are 
resolved  into  simpler  forms. 

As  examples  of  the  more  simple  reactions  of  this  class  we  have 
the  conversion  of  glucose  into  alcohol  and  carbon  dioxide  by  the 
yeast  plant,  the  change  of  lactose  into  lactic  acid  by  the  bacterium 
lactis,  the  change  of  urea  into  ammonium  carbonate  by  the  micro- 
coccus  urese.  More  complex  are  the  changes  in  the  putrefaction 
of  organic  matter  by  such  organisms  as  the  bacterium  termo,  bac- 
terium subtile,  and  the  proteus.  In  many  cases  the  products  of 
the  reaction  are  specific  poisons,  as  is  instanced  by  the  bacilli  of 
anthrax,  of  septicaemia,  diphtheria,  typhoid,  etc.,  etc.  Ptomaines 
are  alkaloidal  substances  formed  in  putrefaction,  while  Toxins  or 
Toxalbumins  are  of  proteid  nature,  and  like  ptomaines  only  in  being 
of  bacterial  origin.  (Leucomaines  are  similar  to  ptomaines  in  com- 
position, being  alkaloidal  in  nature,  but  are  products  of  normal 
metabolism.) 

In  the  putrefaction  of  albumin  we  have  an  instance  of  the  great 
complexity  of  certain  of  the  decompositions.  Among  the  products 
of  the  bacterial  action  here  we  find:  peptones,  ptomaines  such  as 
peptotoxin,  neuridine,  neurine,  choline,  cadaverine,  putrescine, 
etc. ;  nitrogenous  bases,  such  as  leucin,  tyrosin  and  amines;  formic, 
acetic,  propionic,  butyric,  valerianic,  palmitic,  lactic  and  succinic 
acids;  indol,  phenol,  cresol,  pyrocatechol,  hydroquinol,  hydro- 
paracumaric  acid,  etc.,  etc.;  finally,  hydrogen  sulphide,  ammonia, 
carbon  dioxide,  and  water. 

The  Unorganized  ferments  or  Enzymes  are  amorphous,  proteid 
substances,  originating  in  animal  and  vegetable  cell  action.  They 

(87) 


88  FERMENTS  AND  FERMENTATION. 

are  soluble  in  water,  insoluble  in  alcohol,  and  may  be  extracted 
from  their  source  by  water,  by  salt  solution,  or,  best,  by  glycerol. 
They  may  be  classed  as  follows : 

I.  Amylolytic:  ptyalin,  amylopsin,  diastase.     Change  amyloses 
into  sugars.      (Polysaccharids  into  disaccharids. ) 

II.  Proteolytic:    pepsin,    trypsin,    papain.     Change   albumins, 
etc.,  into  peptones. 

III.  Steatolytic:    steapsin.     Decomposes   fats   into   fatty   acids 
and  glycerol. 

1  IV.  Inverting  Enzymes:  invertin.  Changes  cane  sugar,  etc., 
into  glucoses.  (Disaccharids  into  monosaccharids. ) 

V.  Coagulating  Enzymes:  chymosin,  thrombi n,  myosin  ferment. 
Coagulate  proteid  compounds. 

VI.  Glucoside-decomposing  Enzymes:  emulsin  and  myrosin. 

It  will  be  observed  that  many  of  the  enzymes  belong  to  the  class 
of  digestive  ferments.  These  will  be  referred  to  in  more  detail  in 
the  discussion  of  the  digestive  fluids. 

Controlling  Influences  in  Fermentation. — The  living  ferments  and 
the  enzymes  are  both  generally  easily  killed  by  a  moist  heat  of 
100°  C. ,  but  when  perfectly  dry  many  will  stand  a  temperature  of 
from  100°  C.  to  160°  C.  They  are  rendered  quiescent  but  are  not 
killed  by  exposure  to  cold.  A  temperature  of  35°-40°  C.  is  gener- 
ally the  most  favorable  to  both  classes.  Arsenious  oxide,  phenol, 
salicylic  acid,  chloroform  and  ether  will  kill  many  of  the  organized 
ferments,  but  generally  have  a  less  destructive  action  upon  the 
enzymes.  Most  of  the  enzymes  find  their  most  favorable  environ- 
ment in  a  neutral  medium,  or  in  one  that  is  faintly  alkaline; 
pepsin,  however,  requires  a  neutral  or  acid  medium. 


PART  III. 
CLINICAL. 


THE  BLOOD. 


THE  blood  is  an  opaque,  viscid,  reddish  fluid,  with  characteristic 
odor  and  a  salty  taste.  The  Specific  Gravity  averages  about  1.060, 
but  may  vary  from  1.045  to  1.075.  The  Color,  due  to  the  con- 
tained haemoglobin,  varies,  with  the  degree  of  oxidation  of  this 
substance,  from  scarlet  in  arterial  blood  to  bluish-red  in  venous 
blood.  The  depth  of  color  naturally  depends  upon  the  amount 
of  haemoglobin  present  and  therefore  varies  in  certain  diseased 
conditions,  e.  #.,  being  pale  in  chlorosis,  anaemia,  leucaemia,  etc. 
Certain  poisonous  gases  also  affect  the  color,  hydrogen  sulphide 
producing  a  brownish-green  tint,  carbon  monoxide  a  cherry-red, 
chlorine  a  greenish-yellow,  and  arsenetted  hydrogen  a  brown  tint. 
The  Reaction  is  alkaline,  the  alkalinity  being  due  principally  to  the 
disodium  phosphate,  and  sodium  hydrogen  carbonate,  contained. 
Glazed  litmus  paper  may  be  used  in  testing  the  reaction. 

Anatomical  Composition : 

Serum 
Fibrinogen 

Average  0.25  p.  c. 
r  Red  Corpuscles 
•<  Leucocytes 
I  Blood  Platelets 


Blood 


Plasma 

Averages  60  p.  c. 

Corpuscles 

Average  40  p.  c. 


1  Clot, 

including 

I      some   in- 
terstitial 


serum. 


Chemical  Composition  : 
Blood 

Water, 

Solids, 

Albumin, 

Serum-globulin, 

Haemoglobin, 

Fibrinogen, 

Extractives  and  Fat, 

Mineral  Salts, 

1  Becquerel  and  Rodier. 
Schmidt  and  Hoppe-Seyler. 


I.1   Man. 

Blood.1  Woman. 

Serum.2 

Red  Corpuscles8 

(Moist). 

77.90 

79.10 

90.79 

68.80 

22.10 

20.90 

9.21 

31.20 

7.60 

7.60 

I 

4.52 
3.10 

|      2.63 

13.44 

12.18 



27.52 

0.22 

0.22 

0.16 

0.16 

0.71 

0.24 

0.68 

0.74 

0.88 

0.81 

2 Harnmarsten.       'Calculated  from  analyses  by  G. 


(91) 


92  EXAMINATION  OF  BLOOD. 

• 

The  gases  in  human  blood,  measured  at  0°  C.  and  760  mm., 
are  given  as  follows  (Foster):  Arterial  blood;  Oxygen,  20  p.  c., 
Carbon  dioxide,  39  p.  c.,  Nitrogen,  1-2  p.  c.  Venous  blood; 
Oxygen,  8-12  p.  c.,  Carbon  dioxide,  46  p.  c.,  Nitrogen,  1-2  p.  c. 

The  Mineral  Salts  of  blood  consist  of  chlorides,  carbonates, 
phosphates,  and  sulphates  of  sodium  and  potassium,  with  phos- 
phates of  calcium  and  magnesium.  In  the  serum  the  salts  of 
sodium  are  the  more  abundant,  in  the  corpuscles,  the  salts  of 
potassium.  The  iron  from  the  hemoglobin  averages  about  0.05 
per  cent,  of  the  blood. 

THE  PLASMA.  The  plasma  is  a  viscid  yellowish  liquid  with 
strong  alkaline  reaction.  Owing  to  a  change  in  one  of  its  con- 
stituents, Fibrinogen,  it  coagulates  readily,  separating  into  Fibrin 
and  Serum,  the  change  being  effected  by  a  special  unorganized 
ferment,  thrombin,  a  product  of  the  disintegration  of  the  leucocytes 
and  blood  platelets.  The  Fibrin  so  formed  is  an  insoluble,  gray- 
ish-white, string)7  substance,  elastic  and  retractile.  The  coagulation 
is  hastened  by  raising  the  temperature  to  a  little  above  that  of  the 
body,  by  contact  with  most  foreign  matter,  by  agitation,  and  by 
addition  of  a  small  amount  of  a  neutral  salt.  The  coagulation  is 
hindered  by  a  low  temperature,  by  contact  with  a  living  vascular 
surface,  with  oils  and  oily  surfaces,  by  addition  of  a  considerable 
amount  of  a  neutral  salt,  by  small  amounts  of  alkalies,  by  addi- 
tion of  acetic  acid,  by  excess  of  carbon  dioxide  and  by  excess  of 
water.  Coagulation  takes  place  only  in  the  presence  of  calcium 
salts  and  may,  therefore,  be  prevented  by  allowing  the  blood  to 
flow  into  a  solution  of  potassium  oxalate  of  such  strength  that  the 
resulting  mixture  will  contain  about  one-tenth  per  cent,  of  the 
reagent.  The  calcium  salts  are  precipitated  as  calcium  oxalate. 

THE  SERUM  differs  from  the  plasma  only  in  the  absence  of 
fibrinogen,  and  hence  may  be  obtained,  after  coagulation,  as  an 
exudation  from  the  clot,  any  remaining  corpuscles  being  removed 
by  means  of  the  centrifuge.  The  chief  Proteids  of  the  serum  are 
Serum-Albumin  and  Serum-Globulin,  the  latter  being  also  known 
as  Paraglobulin  and  as  Fibrino-plastin.  The  two  may  be  easily 
separated  by  saturation  with  magnesium  sulphate;  the  albumin 
remaining  in  solution  while  the  globulin  is  precipitated. 

The  principal  "Extractives"  of  the  serum  are  the  neutral  fats, 
most  abundant  after  a  meal  of  fatty  food,  and  Cholesterol,  an 
alcoholoid  substance,  C27H45OH,  widely  distributed  in  the  body. 


EXAMINATION  OF  BLOOD.  93 

Lecithin,  a  complex  phosphorus-holding  body  characteristic  of 
nervous  tissue,  is  present  in  the  blood  in  small  amount.  Other 
extractives  are  Urea,  Uric  Acid,  Creatine,  Xanthine,  Hypoxan- 
thine,  Hippuric  Acid,  and  Carbohydrates.  The  Mineral  Salts  of 
the  serum  include  sodium  chloride,  carbonate,  sulphate,  and  phos- 
phate, smaller  percentages  of  the  corresponding  potassium  salts, 
and  phosphates  of  calcium  and  magnesium. 

THE  BLOOD  CORPUSCLES  (!LEMOCYTES).  The  Leucocytes,  also 
known  as  the  "white"  or  "colorless"  corpuscles,  are  typical 
cells  with  nucleus  and  protoplasm.  They  average  from  5-10,000 
per  cubic  mm.  of  blood,  and  vary  in  size  from  0.005  to  0.010  mm. 
in  diameter.  The  protoplasm  of  the  cell  consists  chiefly  of  cell- 
globulin  and  cell-albumin,  but  contains,  also,  glycogen,  fat, 
lecithin,  cholesterol,  and  some  mineral  matter.  The  nucleus  is 
characterized  by  the  presence  of  a  phosphorus-holding  body, 
nuclein.  Various  forms  of  leucocytes  are  recognized:  Large  cells 
with  polymorphic  nuclei,  called  polynuclear;  small  mononuclear 
forms;  and  transitional  forms.  The  leucocytes  are  also  classified 
according  to  the  staining  of  the  contained  granules:  Acidophiles  or 
eosinophiles,  staining  with  acid  stains,  e.  g.  eosin;  basophiles, 
which  stain  with  basic  stains,  e.  g.  methylene  blue;  and  neutro- 
philes,  which  stain  with  neutral  stains,  e.  g.  combined  methylene 
blue  and  eosin.  The  following  methylene-eosin  stain  is  useful  in 
all  cases:  60  parts  of  a  concentrated  water  solution  of  methylene 
blue,  20  parts  of  a  one-half  per  cent,  solution  of  eosin  in  70  per 
cent,  alcohol,  40  parts  of  distilled  water,  and  12  drops  of  20  per 
cent,  potassium  hydroxide. 

The  Blood  Platelets  measure  from  0.002  to  0.004  mm.  in  diam- 
eter. Nothing  definite  is  known  as  to  their  composition.  They 
are  more  numerous  than  are  the  leucocytes. 

The  Red  Corpuscles  (Erythrocytes)  measure  from  0.007  to  0.008 
mm.  in  diameter,  in  man,  and  number  about  5,000,000  per  cubic 
mm. 

Nearly  90  per  cent,  of  the  dried  red  corpuscle  consists  of  Haemo- 
globin, an  iron-holding proteid,  C600H960N154FeS301 79  (Preyer), 
crystalline  but  not  diffusible.  In  arterial  blood  the  haemoglobin 
is  loosely  combined  with  an  additional  molecule  of  oxygen  form- 
ing Oxy haemoglobin,  a  substance  soluble  in  water  and  alkaline 
liquids,  insoluble  in  absolute  alcohol,  ether,  chloroform  and  acids. 
The  additional  oxygen  molecule  may  be  easily  separated  by  means 


94  EXAMINATION  OF  BLOOD. 

of  reducing  agents.  Methasmoglobin,  a  similar  substance  formed 
during  the  drying  of  blood,  and  also  by  the  addition  of  potassium 
ferricyanide,  differs  from  the  last  in  that  the  additional  oxygen  is 
closely  combined.  With  carbon  monoxide,  hemoglobin  forms  a 
cherry-red  combination,  known  simply  as  Carbonic-oxide-haemo- 
globin. Hemoglobin  consists  of  a  brownish  pigment,  Haematin, 
C34H34N4Fe05  (Gautier),  united  with  a  globulin,  the  globin. 
The  pigment  may  be  demonstrated  by  adding  NaOH  to  the  blood. 
By  heating  blood  in  presence  of  glacial  acetic  acid  and  a  little  salt, 
the  Hydrochloride  of  Hsematin,  formerly  known  as  Hsemin,  may  be 
separated  in  dark,  brownish,  triclinic  plates  and  prisms.  Hsema- 
toporphyrin,  C34H34N405  (Gautier),  is  artificially  produced  by  the 
action  of  sulphuric  acid  on  hematin.  It  is  produced  naturally 
within  the  body,  and  is  sometimes  present  in  the  urine.  Hsema- 
toidin,  C32H36N406,  formed  in  old  extravasations,  appears  to  be 
practically  identical  with  bile  pigment. 

ABSORPTION  SPECTRA  OF  BLOOD  PIGMENTS. — In  blood  diluted 
with  250  parts  of  water  Oxyh&moglobin  gives  two  absorption  bands 
between  D  and  E,  that  nearer  D  being  the  narrower  and  darker. 
Haemoglobin  gives  one  broad  band  extending  from  near  E  to  a  little 
beyond  D.  Carbonic-oxide-hgemoglobin  gives  a  spectrum  similar  to 
that  of  oxy haemoglobin,  but  the  bands  are  narrower  and  slightly 
nearer  the  violet  end.  Methaemoglobin  gives  three  bands,  one  in 
the  red  between  C  and  D,  the  others  in  the  position  of  the 
oxyhsemoglobin  bands.  Alkaline  Haematin,  made  by  dissolving 
hematin  in  strong  alkali,  or  by  adding  strong  alkali  to  a  solution 
of  oxy hemoglobin,  gives  one  ill-defined  band  extending  from  D 
toward  C.  Haemochromogen,  a  substance  formed  by  addition  of 
ammonium  sulphide  to  a  solution  of  alkaline  hematin,  gives  one 
band  midway  between  D  and  E,  and  a  second,  fainter,  band  be- 
tween E  and  b.  This  spectrum  is  one  of  the  most  useful  for  pur- 
poses of  identification.  The  band  between  D  and  E  is  given  in 
very  dilute  solutions.  Acid  solution  of  Hsemotoporphyrin  gives  a 
dark  band  midway  between  D  and  E,  and  a  fainter,  narrower, 
band  to  the  left  of  D. 

THE  BLOOD  IN  DISEASE. 

In  Leucocytosis,  physiological  and  pathological,  the  leucocytes 
are  increased.  In  Ansemia  the  red  corpuscles  are  decreased,  and 
there  is  a  proportionate  decrease  in  hemoglobin;  the  leucocytes 


EXAMINATION  OF  BLOOD.  95 

may  be  increased.  In  Pernicious  Ansemia  the  red  corpuscles  are 
greatly  decreased  and  are  irregular  in  size  and  shape  (poikilo- 
cytosis);  the  hemoglobin  is  decreased,  but  not  in  proportion. 
Leucocytes  are  not  materially  increased  and  may  be  normal.  In 
Leucocythasmia  the  leucocytes  are  greatly  increased  and  the  red 
corpuscles  are  slightly  decreased.  In  the  spleno-medullary  form 
of  the  disease  the  increase  is  chiefly  of  the  large  mononuclear  and 
polynuclear  leucocytes.  In  the  lymphatic  form  the  increase  is 
chiefly  of  the  small  mononuclear  leucocytes.  In  Chlorosis  the  red 
corpuscles  may  be  normal  or  slightly  decreased;  the  hemoglobin 
is  greatly  decreased. 

In  haemoglobineemia,  the  haemoglobin  passes  from  the  corpuscles 
to  the  plasma,  and  may  be  present  in  the  urine  (hsemoglobinuria). 
In  septicaemia,  the  haemoglobin  is  reduced  in  amount,  while  there 
is  an  increase  in  the  number  of  leucocytes  and  an  increase  in  the 
amount  of  fat,  urea,  etc.  In  liver  and  biliary  disorders,  bile  pig- 
ment, and  in  obstruction  of  the  bile  ducts,  bile  acids  may  appear 
in  the  blood.  In  acute  yellow  atrophy  of  the  liver,  there  is  a  con- 
siderable amount  of  leucin  and  tyrosin  in  both  blood  and  urine. 
In  kidney  diseases  there  is  often  a  decrease  in  the  percentage  of 
albumin,  while  urea,  fats,  and  fibrin  are  all  increased.  In  diabetes 
mellitus  there  is  an  increased  amount  of  dextrose,  and  ethyldiacetic 
acid  may  be  present. 

EXAMINATION  OF  BLOOD. 

Specific  Gravity. — Prepare  a  mixture  of  chloroform  and  benzol  of 
a  specific  gravity  of  about  1.060,  and  add  a  drop  of  the  blood.  If 
the  drop  rises  to  the  surface,  add  more  benzol;  if  it  sinks,  add 
more  chloroform.  When  the  drop  neither  rises  nor  sinks,  deter- 
mine the  specific  gravity  of  the  mixture. 

Enumeration  of  Corpuscles,  by  the  haernocytometer  of  Gowers  or 
of  Thoma.  For  dilution  of  the  blood  prepare  a  solution  of  sodium 
sulphate,  6.7  grammes,  in  113.5  c.c.  of  water,  with  3.5  c.c.  of" 
acetic  acid,  or  use  a  2.5  per  cent,  solution  of  potassium  dichro- 
mate.  Measure,  by  means  of  the  special  pipette,  995  cubic  mm. 
of  this  solution  into  a  small  glass  vessel.  Prick  the  skin  of  the  ear 
lobe,  or  of  the  finger,  and  draw  up  5  cubic  mm.  of  blood  by 
means  of  a  second,  special,  capillary  pipette.  Blow  the  blood 
from  the  pipette  into  the  vessel  containing  the  saline  solution,  and 
rinse  out  the  pipette  with  the  same  solution.  Stir  the  mixture 


^6  EXAMINATION  OF  BLOOD. 

;and  place  one  drop  of  it  on  the  slide  of  the  instrument.  This 
slide  is  ruled  into  squares  (in  the  Thoma  cell  each  millimetre  is 
divided  into  400  squares  in  sets  of  16)  and  so  arranged  that  with 
the  cover  glass  in  position  the  blood  film  is  one-tenth  of  a  mm.  in 
depth.  Count  the  corpuscles  in  about  50  squares.  Determine 
the  average  number  per  square  and  (in  case  of  the  Thoma  cell) 
multiply  this  by  4000  to  obtain  the  number  of  corpuscles  per 
•cubic  mm.  Multiply  again  by  200  to  obtain  the  number  of  cor- 
puscles per  cubic  mm.  of  undiluted  blood.  In  one  form  of 
•Gower's  cell  each  square  represents  one-five-hundredth  of  a  cubic 
mm.,  hence,  the  average  number  of  corpuscles  in  each  square,  in 
this  case  (the  blood  being  diluted  200  times  as  before),  must  be 
multiplied  by  500  X  200  to  obtain  the  number  of  corpuscles  in  one 
•cubic  millimetre  of  undiluted  blood.  For  diluting  the  blood  the 
'Thoma-Zeiss  apparatus  has  a  pipette  graduated  at  0.5,  1.0,  and 
101.  cu.  mm.  The  blood  is  drawn  up  to  the  0.5,  or  1.0  mark,  and 
the  diluting  liquid  to  the  101.  mark.  If  0.5  cu.  mm.  of  blood  is 
taken,  the  average  number  of  corpuscles  per  square  is  to  be  multi- 
plied by  4000  X  200;  while  if  1.0  cu.  mm.  of  blood  is  taken,  the 
number  of  corpuscles  per  square  is  to  be  multiplied  by  4000X100. 

The  proportion  of  white  to  red  corpuscles  may  be  approximately 
ascertained  during  the  counting,  the  saline  solution  rendering 
prominent  the  nuclei  of  the  white  corpuscles.  To  differentiate  the 
several  kinds  of  white  corpuscles,  neutrophiles,  eosinophiles,  etc. , 
it  is  necessary  to  prepare  a  stained  specimen  of  the  blood.  For 
the  methods  of  staining,  and  for  description  of  these  cells,  see  page 
93  and  text-books  of  histology. 

The  centrifuge  with  haamatocrit  attachment  affords  an  easy  and 
rapid  approximate  method  for  the  enumeration  of  corpuscles. 
Ample  instructions  accompany  the  instrument. 

Estimation  of  Haemoglobin,  by  the  hasrnoglobinometer  of  Gowers. 
Two  glass  tubes  are  provided,  one  graduated  into  120  parts  for 
the  blood,  the  other  containing  a  preparation  of  glycerine  jelly  so 
tinted  with  carmine  and  picrocarmine  that  its  color  is  that  of 
normal  blood  diluted  with  100  parts  water.  Twenty  cubic  mm. 
•of  blood  are  measured  by  means  of  a  capillary  pipette  into  a  few 
•drops  of  distilled  water  previously  placed  in  the  graduated  tube. 
'The  blood  is  then  diluted  until  the  tint  is  the  same  as  that  of  the 
standard.  If  the  blood  be  diluted  to  the  100  mark  then  the 
liaBmoglobin  is  normal;  if  to  the  50  mark,  then  one-half  normal, 


TESTS  FOR  BLOOD.  97 

etc.  It  is  important  to  compare  the  amount  of  haemoglobin  with 
the  number  of  red  corpuscles.  The  percentage  of  haemoglobin 
divided  by  the  percentage  of  red  corpuscles  gives  the  Color  Ratio  or 
Index.  Thus,  in  a  case  of  chlorosis,  the  haemoglobin  was  30  p.  c. 
of  the  normal,  the  red  corpuscles  were  90  p.  c.  of  the  normal  and 
the  Color  Ratio,  f£  or  0.3  +. 

Estimation  of  Haemoglobin  from  the  contained  iron.  Evaporate  a 
weighed  quantity  of  blood  to  dryness,  ignite  at  a  dull  red  heat, 
treat  the  residue  with  hydrochloric  acid  and  determine  the  iron 
quantitatively.  If  x  equal  the  percentage  of  iron,  then  the  per- 
centage of  haemoglobin  in  the  sample  equals  x  multiplied  by  100, 
divided  by  0.42. 

TESTS  FOR  BLOOD. 

The  suspected  solution  may  be  examined  microscopically  for 
blood  corpuscles,  and  spectroscopically  for  blood  pigment.  If  the 
blood  be  fresh  the  spectrum  of  oxyhaemoglobin  may  be  obtained; 
older  blood  will  probably  show  methaemoglobin.  In  the  case  of 
stains  on  cloth,  extract  with  a  little  water,  add  a  few  drops  of 
sodium  hyposulphite,  NaHS02,  a  few  drops  of  strong  sodium  hy- 
droxide, and  then  examine  for  the  spectrum  of  hsemochromogen. 

The  Guaiacum  Test.  Mix  the  suspected  fluid  with  3-4  drops  of 
a  freshly  prepared  tincture  of  guaiacum  resin.  Float  an  etherial 
solution  of  hydrogen  dioxide  on  the  surface  of  the  mixture,  and 
let  it  stand  without  shaking.  In  presence  of  haemoglobin  the 
etherial  layer  will  turn  blue. 

The  guaiacum  test  is  given,  more  or  less  perfectly,  by  substances 
other  than  blood,  e.  #.,  by  milk,  pus,  saliva,  various  mineral  com- 
pounds, oxidizing  agents,  etc.,  but  in  most  cases  the  blue  color  is 
obtained  on  addition  of  the  guaiacum  alone,  while  with  blood  no 
color  is  obtained  until  after  the  addition  of  the  dioxide.  Old  oil 
of  turpentine  that  has  been  well  exposed  to  light  and  air  may  be 
used  instead  of  the  etherial  hydrogen  dioxide  solution. 

The  "Hxmin"  and  Other  Tests.  To  a  drop  of  fresh  blood  on  a 
glass  slide  add  a  drop  or  so  of  glacial  acetic  acid  and  heat  slowly 
to  boiling.  Cool  and  examine  under  the  high  power  of  the  micro- 
scope for  crystals  of  haematin  hydrochloride,  "hsernin,"  minute 
dark  brown  triclinic  plates  and  prisms,  often  in  star-shaped  clusters. 

In  the  examination  of  a  stain  on  cloth,  etc.,  scrape  the  stain  and 
place  the  scrapings  (or  place  a  few  fibres  of  the  stained  material) 


98 


TESTS  FOE  BLOOD. 


on  a  large  glass  slide.  Add  2-3  small  crystals  of  sodium  chloride, 
and  a  few  drops  of  glacial  acetic  acid;  warm  gently  for  some  time, 
then  add,  to  the  evaporated  solution,  two  drops  more  of  the  acid, 
and  heat  to  boiling.  Cover  with  a  cover  glass  and  examine  for 
the  crystals.  The  treatment  with  acetic  acid  may  advantageously 
be  repeated  several  times. 

As  a  sequel  to  the  hsemin  test,  dissolve  the  crystals  obtained,  in 
a  few  drops  of  sodium  hydroxide.  If  sufficient  hsemin  be  pres- 
ent, the  solution  is  dichroic,  green  and  red.  Evaporate  to  dryness 
in  ?,  small  porcelain  crucible  and  test  the  residue  for  iron. 

A  stain  may  be  further  tested  as  follows:  Soak  the  stain  in 
water  and  place  drops  of  the  aqueous  solution  on  a  number  of 
watch  glasses.  To  one  add  nitric  acid,  to  another  add  acetic  acid 
and  potassium  ferrocyanide;  if  the  stain  be  recent,  precipitates 
should  be  obtained  in  both  tests.  To  a  third  portion  add  a  drop 
of  ammonium  hydroxide;  the  red  color  remains,  while  with  vege- 
table reds  it  would  probably  be  destroyed.  Heat  to  boiling — a 
gray  turbidity  is  produced — add  a  few  drops  of  sodium  hydroxide 
— the  turbidity  disappears  and  the  solution  exhibits  the  green-red 
dichroism. 

For  tests  for  blood  in  the  urine,  see  under  Urine  Analysis. 


THE  URINE. 


Constituents  of  Normal  Urine. — Urea  and  related  substances;  uric 
acid,  xanthine,  creatinine,  etc.  Compounds  of  fatty  acids  and 
traces  of  other  non-nitrogenous  substances,  including  carbohy- 
drates. Aromatic  substances;  etherial  sulphates  of  phenol,  cresol, 
pyrocatechol,  indoxyl  and  skatoxyl ;  hippuric  acid,  etc.  Pig- 
ments and  ferments.  Mineral  substances  ;  chlorides,  sulphates 
and  phosphates  of  sodium,  potassium,  calcium  and  magnesium, 
ammonium  compounds,  and  carbonates.  Gases;  nitrogen,  carbon 
dioxide  and  traces  of  oxygen. 

Abnormal  Constituents. — Serum  albumin  and  other  proteids; 
blood  and  bile  pigments,  bile  acids,  abnormal  urinary  pigments; 
glucose,  lactose,  and  glycuronic  acid;  leucin  and  tyrosin;  fats, 
lecithin,  cholesterol,  cystin;  blood  corpuscles,  pus,  casts,  renal 
epithelium,  etc. 

According  to  the  author's  analyses  a  man  weighing  65  kilo- 
grammes will  pass,  in  24  hours,  an  average  of  1480  c.c.  of  urine 
with  a  specific  gravity  of  1020,  the  average  amounts  of  the  dis- 
solved substances  being  about  as  follows:  In  a  total  of  60  grammes, 
we  have — 


Urea, 

34.  0  grammes. 

Uric  Acid, 

0.6 

Creatinine, 

0.9 

Hippuric  Acid, 

0.7 

Other  Organic 

Constituents, 

2.3         " 

Total  Organic, 

38.5  grammes. 

Chlorine, 


7. 3  grammes. 


Phosphorus  Pen- 

toxide,  .  .3.0 

Sulphur  Trioxide.  2.2 

Potassium  Oxide,  3.0 

Sodium  Oxide,  4.5 

Calcium  Oxide,  0.3 

Magnesium  Oxide,  0.4 
Other  Inorganic 

Constituents,  0. 8 


Total  Inorganic, 
(99) 


2 1.5  grammes. 


100  URINE  ANALYSIS. 

GENERAL  PLAN  OF  CLINICAL  URINARY  ANALYSIS. 
I.  Ascertain  Quantity  passed  in  24  hours,  and  obtain  an 

average  Sample. 
II.   Note  Color,  Appearance  and  Odor. 

III.  If  turbid,  test  Character  of  Sediment. 

IV.  Test  Reaction  with  litmus  paper. 
V.   Determine  the  Specific  Gravity. 

VI.   Calculate  the  Total  Solids. 

VII.  Set  aside  a  sample  for  Microscopic  Examination;  filter 
the  remainder  of  the  urine  and  use  filtered  urine  for 
the  following  tests: 
VIII.  Test  for  Mucin. 

IX.   Test  for  Albumin,  and,  if  present,   determine  amount. 
Heat  the  urine  to  boiling,  cool,  filter,  and  use  the  al- 
bumin-free filtrate  for  the  following  tests: 
X.  Test  for  Sugar,  and,  if  present,  determine  the  amount. 
XL   Determine    the    amount    of    Urea.       (In   albumin-free 

Urine. ) 
XII.   Determine  the  approximate  amount  of  Chlorides. 

XIII.  Determine  the  approximate  amount  of  Sulphates. 

XIV.  Determine  the  approximate  amount  of  Phosphates. 
XV.  Test  for  "Indican." 

XVI.   Test  for  Bile  and  for  Blood. 
XVII.   Make  Microscopic  Examination  of  the  Sediment. 

NOTES  ON  THE  CLINICAL  ANALYSIS. 
QUANTITY. 

An  adult  man  passes  on  an  average,  1300  to  1600  c.c.  of  urine 
in  24  hours.  Women  secrete  less  than  men;  children  absolutely 
less  but  relatively  more,  about  60  c.c.  for  each  kilogramme  of 
body  weight  (man,  about  23  c.c.  for  each  kilo).  The  urine  is 
increased  after  the  ingestion  of  much  liquid,  reaching  2000  to  3000 
c.c.  It  is  increased,  also,  in  nervous  excitement,  hysteria,  chorea, 
in  forms  of  diabetes,  in  chronic  interstitial  nephritis,  and  in 
amyloid  kidney.  It  is  diminished  by  profuse  perspiration,  hence 
in  summer,  by  abstinence  from  liquid  food,  by  sleep,  often  in 
valvular  disease,  acute  inflammations,  fever,  diarrhoea,  enteritis, 
etc. ;  in  acute  nephritis,  often  in  chronic  parenchymatous  nephritis, 
and  in  uremia. 

The  sample  selected  for  analysis,  owing  to  variation  in  the  com- 


URINE  ANALYSIS.  101 

position  of  the  urine  during  the  day,  should  be  an  average  of  that 
passed.  If  the  average  sample  is  not  obtainable,  note  the  time  of 
passing;  night,  morning,  before  or  after  a  meal,  etc. 

COLOR,  APPEARANCE  AND  ODOR. 

Normal  urine  is  described  as  clear,  straw-yellow,  sherry  colored, 
or  amber.  It  varies  normally  in  shade  from  nearly  colorless  to 
dark  amber.  The  pigment  has  been  variously  designated  but  may 
best  receive  the  non-committal  name  of  Urochrome.  A  modifica- 
tion of  the  normal  pigment  occurs  in  disease  and  is  described  as 
febrile  Urobilin.  The  urine  is  light  colored  after  ingestion  of  a  large 
amount  of  water,  in  nervous  conditions,  and,  generally,  whenever 
the  urine  is  greatly  increased  in  amount;  it  is  often  nearly  colorless 
in  diabetes.  It  is  dark  after  profuse  perspiration,  muscular  ac- 
tivity, etc.,  and  in  acute  febrile  conditions.  It  may  be  red  or 
brown  from  presence  of  blood  pigments,  or  greenish- yellow,  brown,  to 
black  from  presence  of  bile.  " Blue"  urine  is  sometimes  observed 
in  cholera  and  in  typhus.  Again,  the  color  may  be  due  to  drugs 
ingested;  phenol  and  gallic  acid,  producing  a  black  urine;  santonin, 
chrysophanic  acid,  rhubarb,  senna,  etc.,  an  orange  to  yellow  urine; 
sulphonal,  a  dark-red  urine. 

In  case  the  color  be  so  pronounced  as  to  interfere  with  the  chem- 
ical tests,  the  urine  should  be  decolorized  by  shaking  with  pow- 
dered animal  charcoal  arid  filtering. 

The  urine  is  usually  clear  when  passed,  though  a  faint  cloudi- 
ness is  not  uncommon.  All  urines  become  turbid  on  standing. 
A  turbidity  may  be  due  to  an  excess  of  mucus,  to  pus,  chyle, 
semen,  phosphates,  urates,  etc.  By  heating,  the  turbidity  due  to 
phosphates  is  slightly  increased,  but  it  disappears  at  once  on  the 
addition  of  a  few  drops  of  nitric  acid  or  of  acetic  acid.  By  heat- 
ing the  turbidity  due  to  urates  disappears.  If  due  to  pus,  the 
turbidity  is  increased  by  heat. 

The  odor  of  normal  urine  is  described  as  aromatic.  After  stand- 
ing, however,  it  may  become  ammoniacal.  Asparagus,  turpentine, 
cubebs,  valerian,  and  garlic,  all  impart  characteristic  odors.  The 
urine  of  diabetes  has  often  a  sweet  odor,  due  generally  to  presence 
of  acetone;  that  of  albuminuria,  after  standing,  a  fetid  odor. 

REACTION. 
The  reaction  of  an  average  sample  of  normal  urine  is  always 


102 


URINE  ANALYSIS. 


acid;  the  total  acidity  in  terms  of  oxalic  acid  being  2-4  gra 
for  the  24  hours.  The  acidity  is  reduced,  or  the  urine  may  be- 
come alkaline,  after  hearty  meals,  hot  baths,  administration  of 
alkaline  salts,  etc.,  with  a  strictly  vegetable  diet,  in  general 
debility,  chlorosis,  or  anemia.  The  acidity  is  increased  with  a 
meat  diet,  by  muscular  activity,  in  fevers,  typhus,  and  often  in 
pneumonia. 

Upon  standing  the  urine  may  at  first  become  more  acid,  with 
decomposition  of  urates,  but  later  an  alkaline  fermentation  sets  in, 
the  urea  is  decomposed  and  ammonium  carbonate  formed.  At 
this  stage  the  turbidity  is  increased  by  precipitation  of  phosphates, 
and  an  ammoniacal  odor  is  noticeable. 

Test  the  reaction  of  the  urine  with  litmus  paper.  If  an  alkaline 
reaction  be  obtained  (red  litmus  turns  blue)  dry  and  warm  the 
paper.  If  the  alkalinity  be  due  to  fixed  alkalies  the  blue  color 
will  remain  after  warming  and  the  alkalinity  is  referable  to  the 
blood.  If  the  blue  color  disappears  on  warming,  the  alkaline  re- 
action is  due  to  the  ammonium  compounds  formed  in  the  urine  by 
decomposition  of  the  urea. 

Total  Acidity  of  the  Urine. — To  50  c.c.  of  urine  add  several  drops 
of  phenolphthalein,  and  titrate  with  decinormal  potassium  hy- 
droxide until  the  pink  color  appears.  Each  c.c.  of  the  decinormal 
alkali  is  equivalent  to  0.006285  grammes  of  oxalic  acid.  *  Assum- 
ing that  the  50  c.c.  of  urine  weigh  50  grammes,  the  percentage 
may  be  easily  calculated.  In  case  the  urine  is  highly  colored,  it 
is  best  first  to  remove  the  color  by  shaking  with  purified  animal 
charcoal  and  filtering. 

It  is  to  be  remembered  that  the  acid  reaction  of  the  urine  is  in 
reality  due  to  the  presence  of  acid  salts,  NaH2PO4,  etc.,  and  not 
at  all  to  oxalic  acid,  this  last  substance  being  generally  adopted, 
however,  because  of  the  greater  case  in  calculation  and  as  affording 
a  simple  means  of  comparison. 

SPECIFIC  GRAVITY. 

The  specific  gravity  of  normal  adult  urine  varies  generally  be- 
tween 1010  and  1030,  with  an  average  of  1020  for  1500  c.c.  passed. 
In  children  from  two  to  thirteen  years  of  age  the  average  is  about 
1012. 

In  order  that  the  determination  of  the  specific  gravity  shall  be 
of  value,  it  is  necessary  to  know  the  amount  passed  and  to  use  an 
average  sample. 


URINE  ANALYSIS.  103 

When  the  amount  passed  varies  from  the  normal  (1500  c.c.)  the  specific  grav- 
ity of  the  average  sample  may  be  reduced  to  the  normal  by  the  formula  :  — 


In  which  A  equals  the  amount  passed,  G  equals  the  last  two  figures  of  the  ob- 
served specific  gravity,  and  D  equals  the  specific  gravity  of  the  urine  reduced  to 
the  normal  quantity.  Thus,  suppose  3000  c.c.  were  passed,  and  the  specific 
gravity  of  the  average  sample  to  be  1015. 

3000  X  15 

+  100°  =  103° 


Reduced  to  the  normal,  then,  of  1500  c.c.,  the  specific  gravity  is  1030,  showing 
that  while  the  specific  gravity  of  the  original  sample  was  low,  the  total  solids 
are  in  reality  high. 

Note,  however,  that  in  calculations,  e.  g.,  in  calculating  the  total  solids,  the 
observed,  not  the  revised,  specific  gravity  must  be  used. 

Considered  with  the  amount  passed  in  24  hours,  the  specific 
gravity  gives  the  following  indications:  A  decreased  amount  with 
increased  specific  gravity  indicates  diminished  secretion,  loss  of 
water  by  other  excretions,  or  the  presence  of  some  morbid  process. 
acute  nephritis,  fever,  etc.  An  increased  amount  with  decreased 
specific  gravity  indicates  abundant  ingestion  of  water,  absorption  of 
exudations,  or  some  form  of  diseased  kidney.  A  decreased  amount 
with  decreased  specific  gravity  indicates,  possibly,  uremia,  or  chronic 
parenchymatous  nephritis.  An  increased  amount  with  increased 
specific  gravity  may  indicate  diabetes  mellitus. 

The  specific  gravity  is  usually  determined  by  means  of  the 
urinometer,  a  small  hydrometer  with  special  scale.  This  scale  is 
adjusted  to  give  accurate  readings  at  a  certain  temperature  (usually 
60°  F.  )  marked  upon  the  instrument,  and  as  the  temperature  of 
the  urine  tested  is  nearly  always  above  this,  it  is  necessary,  in  ac- 
curate determinations,  to  make  a  corresponding  correction.  The 
temperature  of  the  urine  is  determined  and  for  each  6°  above 
60°  F.,  one  is  added  to  the  observed  specific  gravity.  Thus  the 
corrected  specific  gravity  for  a  urine  reading  1020  at  72°  F.  is 
1022.  For  more  accurate  determinations  it  is  necessary  to  use  the 
pycnometer,  for  which,  see  works  on  physics. 

TOTAL  SOLIDS. 

The  solids  in  the  normal  urine  of  24  hours  vary  from  45-65 
grammes,  with  an  average  for  the  male  adult  of  about  60  grammes  . 
(926  grains).     In  practice,  however,  age,  sex,  diet  and  exercise 


104  URINE  ANALYSIS. 

must  be  considered,  and  a  proper  figure  adopted  for  each  case 
under  observation.  For  differences  in  age,  deduct  one-tenth  for 
each  ten  years  after  forty.  For  light  diet  or  for  fasting,  deduct 
from  one-tenth  to  one-third.  For  confinement  to  bed,  deduct 
one-tenth;  for  confinement  to  the  house,  deduct  one-twentieth. 
The  solids  may  be  calculated  with  sufficient  accuracy  for  clinical 
purposes  by  multiplying  the  last  two  figures  of  the  specific  gravity 
by  Haser's  coefficient,  2.33.  The  product  gives  the  number  of 
grammes  in  1000  c.c.  of  the  urine,  and  from  this  the  number  of 
grammes  in  the  urine  passed  may  be  easily  calculated.  Other 
factors,  or  coefficients,  which  have  been  proposed  are,  Trapp's  = 
2,  and  that  of  Loebisch  =  2.2.  Haser's  coefficient  is  that  most 
often  used,  though  probably  the  coefficient  of  Loebisch,  or  the  even 
simpler  one  of  Trapp,  will  give  nearer  to  the  true  amount  of  total 
solids.  For  the  urine  of  young  children,  the  coefficient  1.80 
should  be  used.  In  English  measure  the  number  of  grains  of  total 
solids  in  24  hours  may  be  roughly  calculated  by  multiplying  the 
last  two  figures  of  the  specific  gravity  by  the  number  of  fluid 
ounces  passed. 

MUCIN. 

Mucin  is  present  in  small  amount  in  normal  urines,  but  it  is 
greatly  increased  by  irritation  of  the  urinary  tract.  It  is  precipi- 
tated by  addition  of  acetic  acid  in  the  cold  (unlike  albumin). 
Mucin  is  not  precipitated  by  boiling,  but  is  precipitated  by  dilute 
mineral  acids,  as  well  as  by  acetic,  citric,  and  other  organic  acids. 
Mucus  in  excess  in  acid  urine  presents  itself  as  a  flocculent  amor- 
phous mass,  easily  soluble  in  sodium  hydroxide.  See,  also,  under 
Urinary  Sediments. 

ALBUMIN. 

Normal  urine  is  free  from  proteids,  but,  on  the  other  hand,  the 
presence  of  a  trace  of  albumin  is  not  necessarily  always  of  serious 
import.  Temporary  albuminuria  may  occur  after  severe  bodily 
exertion,  after  the  shock  of  a  cold  bath,  from  excess  of  albuminous 
foods,  from  the  presence  of  semen,  etc.  When  more  than  a  trace 
is  present,  or  when  this  trace  persists  for  a  considerable  time,  the 
existence  of  a  serious  abnormal  condition  is  indicated.  Serum 
albumin  and  serum  globulin  are  the  forms  of  proteid  most  fre- 
quently met  with,  while  ha3moglobulin,  fibrinogen,  peptones  and 
proteoses  may  also  appear.  In  general,  the  immediate  cause  of 


URINE  ANALYSIS.  105 

albumin  in  the  urine  may  be  stated  as  impaired  circulation 
through  the  glomeruli  of  the  kidney,  a  result  of  either  venous  or 
ail crial  disorder,  of  changes  in  the  blood  itself,  or  of  diseased 
condition  of  the  kidney.  The  albuminuria  of  pregnacy,  like  that 
due  to  ovarian  or  uterine  tumors,  is  generally  a  result  of  disordered 
venous  reflux,  and  the  same  may  be  said  of  the  albuminuria  of 
heart  disease.  Albumin  may  occur  in  gout,  in  scarlet  fever,  diph- 
theria, pneumonia,  and  as  a  result  of  irritant  poisoning.  It  is 
typical  in  Bright' s  disease.  In  acute  parenchymatous  nephritis 
there  is  considerable  albumin  and  often  blood,  the  urine  is  de- 
creased and  the  specific  gravity  is  high.  In  chronic  parenchym- 
atous nephritis  there  is  considerable  albumin,  the  urine  is  normal 
or  decreased,  and  the  specific  gravity  is  generally  low.  In  chronic 
interstitial  nephritis  the  urine  is  increased,  the  specific  gravity  is 
low,  and  the  albumin  is  small  in  amount.  In  amyloid  degenera- 
tion the  urine  is  increased,  the  specific  gravity  is  low,  and  there  is 
considerable  albumin.  In  acute  interstitial  nephritis  both  the 
amount  of  urine  and  the  specific  gravity  are  decreased,  while  the 
albumin  is  variable. 

Among  other  diseases  giving  rise  to  albuminuria  may  be  men- 
tioned cystic  disease  of  the  kidney,  acute  and  passive  renal  hyper- 
ffimia,  renal  tuberculosis,  calculus,  uremia,  hydronephrosis  and 
pyonephrosis. 

HEAT  TEST.  A  long  test-tube  is  three-quarters  filled  with  clear 
acid  urine  and  the  upper  half  of  this  is  carefully  heated  to  boiling. 
A  cloudiness  appearing  in  the  heated  portion  may  be  due  to  albu- 
min or  to  phosphates.  Add  a  few  drops  of  dilute  nitric  acid, 
phosphates  will  be  dissolved  and  any  cloudiness  remaining  will  be 
due  to  albumin. 

Precautions. — If  the  urine  is  not  already  acid,  acidify,  before 
heating,  by  addition  of  a  few  drops  of  dilute  nitric  acid.  Acetic 
acid  may  be  used,  but  has  the  double  disadvantage  of  being  more 
likely  to  cause  the  solution  of  a  trace  of  albumin  than  nitric,  and 
also  of  precipitating  mucin.  A  cloudiness  appearing  only  after 
some  minutes  may  be  due  to  albumoses.  Urates,  if  abundant, 
sometimes  separate  on  cooling,  but  are  not  likely  to  be  mistaken 
for  albumin.  The  addition  of  nitric  acid  after  boiling  should  be 
continued  until  one  drop  has  been  added  for  each  c.c.  of  urine. 

NITRIC  ACID  CONTACT  TEST.  Place  some  pure  nitric  acid  in  a. 
test-tube,  and  float  over  it  carefully,  by  means  of  a  pipette,  an 


106  URINE  ANALYSIS. 

equal  volume  of  the  urine  to  be  tested.     A  white  zone  or  ring  at 
the  contact  of  the  two  liquids  indicates  albumin. 

Precautions.  —  A  pink,  red,  or  brown  color  may  appear  at  the 
contact,  due  to  action  of  the  acid  on  the  coloring  matters  of  the 
urine.  When  cold  acid  is  used  in  the  test,  crystalline  nitrate  of 
urea  may  separate  at  the  contact,  or  acid  urates  may  cause  a 
cloudiness  just  above.  Resinous  matters,  if  present,  as  after  in- 
gestion  of  turpentine,  balsams,  etc.,  may  cause  a  yellowish-white 
zone,  which  is  unlike  albumin,  however,  in  being  soluble  in  alco- 
hol. Albumose  is  precipitated  by  nitric  acid  in  the  cold,  dissolves 
on  heating,  and  reappears  when  cooled. 

FERROCYANIDE  TEST.  To  a  little  acetic  acid  in  a  test-tube  add 
2—3  volumes  of  potassium  ferrocyanide,  and  then  add  the  urine. 
Albumin  is  separated  as  a  milky  or  flocculent  precipitate.  Purdy 
claims  that  this  test  is  given  by  albumin  and  its  modifications, 
but  not  by  other  urinary  ingredients. 

PICRIC  ACID  TEST.  Warm  some  picric  acid  solution  in  a  test 
tube  and  add  the  urine  to  it,  drop  by  drop.  A  slight  opalescence 
as  each  drop  of  urine  enters  the  acid  indicates  albumin.  This 
test  may  also  be  performed  by  the  contact  method,  floating  the 
acid  over  the  urine. 

Precaution. — If  cold  acid  be  used,  peptones,  mucin,  and  alka- 
loids, may  also  be  precipitated.  With  the  warm  acid  the  test  is 
exceedingly  delicate. 

In  a  highly  acid  urine  picric  acid  may  cause  the  separation  of 
urates,  and,  sometimes,  of  uric  acid. 

For  other  tests,  see  Albumin,  p.  78. 

QUANTITATIVE  ESTIMATION.  The  quantitative  estimation  of  al- 
bumin is  difficult,  and  an  accurate  determination  is  rarely  possible 
in  the  ordinary  clinical  analysis.  A  rough  comparison  of  the 
amount  of  albumin  in  the  urine  from  day  to  day  may  be  made 
from  the  bulk  of  coagulum  obtained  by  the  heat  test,  using  always 
the  same  size  tube  and  the  same  amount  of  urine.  A  more  accu- 
rate estimation  may  be  made  with  Esbadi's  Albuminometer.  The 
urine,  diluted  with  a  known  volume  of  water,  if  there  be  much 
albumin,  is  introduced  into  the  tube  to  the  mark  U,  and  Esbach's 
reagent  (see  Appendix)  added  to  the  mark  R.  The  reagent  is 
mixed  with  the  urine,  the  tube  stoppered  and  allowed  to  stand  24 
hours.  The  volume  of  the  precipitate  measured  by  the  gradua- 
tions, gives  the  percentage  of  albumin.  Each  main  division  equals 


URINE  ANALYSIS.  107 

0.1  per  cent.     There  is  rarely  more  than  1.0  per  cent,  of  albumin 
present. 

A  still  more  accurate  method  is  the  following:  The  urine  is  di- 
luted with  (.»  volumes  of  water,  and  from  this  diluted  urine  (one- 
tent  li  urine)  test  solutions  are  prepared,  each  containing  10  c.c. 
of  water  and  a  measured  volume  of  the  one-tenth  urine;  e.y,, 

(1)  Contains  10  c.c.  of  water  plus  1  c.c.  of  the  one-tenth  urine; 

(2)  Contains  10  c.c.  of  water  plus  2  c.c.  of  the  one-tenth  urine, 
etc.     Nitric  acid  contact  tests  are  now7  made  with  each  test  solu- 
tion until  one  is  found  which  responds  only  after  standing  for  2-3 
minutes.     The  percentage  of  albumin  in  the  original  urine  may  be 
calculated  from  the  formula: 


30V 

In  which  V  equals  the  volume  of  one-tenth  urine  added  to  the  10 
c.c.  of  water,  and  P  equals  the  percentage  sought.  For  instance, 
if  to  the  test  solution,  which  produces  a  zone  of  coagulum  only 
after  standing  2-3  minutes,  5  c.c.  of  the  one-tenth  urine  had  been 
added,  then  the  percentage  of  albumin  originally  present  is 

10  +  5 

OQ  x  r  =  0.  10  per  cent. 

SUGAR  IN  URINE. 

Transitory  glycosuria  may  occur  in  cerebro-spinal  meningitis,  in 
epilepsy,  from  brain  injuries,  under  the  influence  of  strong  emo- 
tion, in  pneumonia,  ague,  gout,  in  cholera,  in  disease  of  the 
pancreas,  and  after  excessive  use  of  saccharine  food.  Lactose  is 
frequently  present  in  the  urine  of  mothers  during  the  weaning 
period.  Cane  sugar  may  appear  after  ingestion  of  large  quantities 
of  that  carbohydrate.  Permanent  glycosuria  is  generally  considered 
as  indicative  of  diabetes.  In  general,  diabetic  urine  is  pale  straw- 
colored,  with  sometimes  a  greenish  tint;  it  is  often  turbid  and  may 
have  a  sweetish  odor.  The  specific  gravity  is  high  (1030-1050) 
and  the  quantity  passed  is  seldom  less  than  1GOO  c.c.  in  24  hours. 
It  may  vary,  however,  between  the  extreme  limits  of  500  c.c.  and 
8000  c.c.  Diabetes  mellitus  with  polyuria,  is  far  more  serious 
than  without,  and,  indeed,  glycosuria  without  polyuria  does  not 
seem  to  be  necessarily  fatal.  The  percentage  of  sugar  varies  from 
2-3  per  cent,  to  12  per  cent. 


108  URINE  ANALYSIS. 

TROMMER'S  TEST.  Add  to  the  urine  in  a  test-tube  about  one- 
fourth  its  volume  of  sodium  hydroxide,  and  then  dilute  copper 
sulphate,  drop  by  drop,  until  a  slight  permanent  precipitate  is 
formed.  In  the  presence  of  glucose  the  bluish-white  precipitate 
of  cupric  hydroxide  first  formed  dissolves  on  agitation,  producing 
a  dark-blue  solution.  Heat  the  liquid  and,  in  presence  of  glucose, 
yellow  cuprous  hydroxide  and  red  cuprous  oxide  are  precipitated 
just  as  the  liquid  begins  to  boil.  The  same  precipitation  takes 
place  without  heating,  but  much  more  slowly. 

Precautions. — A  normal  urine  will  often  decolorize  the  solution, 
but  no  red  precipitate  is  formed.  The  sodium  hydroxide  causes  a 
precipitation  of  flocculent  phosphates,  which,  however,  bear  no 
resemblance  to  the  granular  cuprous  precipitate.  A  precipitate  of 
yellow  cuprous  hydroxide,  which  separates  on  the  cooling  of  the 
test,  may  not  be  due  to  sugar.  Uric  acid,  hippuric  acid,  creatinine, 
xanthine  bases,  and  mucin  may  cause  a  partial  reduction  of  the 
copper  solution.  Glycuronic  acid  produces  a  complete  reduction. 
The  presence  of  albumin,  peptones,  etc. ,  interferes  with  the  deli- 
cacy of  the  test.  When  there  is  but  a  slight  reduction,  greater 
accuracy  may  be  attained  by  clarifying  the  urine  with  animal 
charcoal  or  lead  acetate,  filtering,  and  testing  the  filtrate. 

FEHLING'S  TEST,  HAINES'  TEST,  ETC.  (See  Appendix  for  the 
solutions. ) 

Boil  four  or  five  c.c.  of  the  solution  in  a  test-tube  and  add  the 
urine  drop  by  drop.  A  yellowish-red  precipitate,  as  in  Trommer's 
test,  indicates  glucose. 

Precautions. — The  test  solution,  which,  in  the  case  of  Fehling's, 
is  to  be  diluted  with  about  three  volumes  of  water,  should  remain 
clear  when  boiled  before  addition  of  the  urine.  In  Haines'  test 
not  more  than  about  eight  drops  of  urine  should  be  added.  The 
precautions  given  under  Trommer's  test  apply  here  also,  and 
should  be  carefully  observed. 

As  regards  the  relative  value  of  Haines'  and  Fehling's  solutions, 
it  may  be  remarked  that  Haines'  solution  is  less  liable  to  decom- 
position than  is  Fehling's  completed  solution.  It  is  best,  however, 
to  preserve  Fehling's  solution  in  two  parts,  as  described  in  the 
Appendix,  and  to  mix  only  a  sufficient  amount  for  each  test. 

BOTTGER'S  BISMUTH  TEST.  To  a  few  c.c.  of  the  urine  in  a  test- 
tube,  add  an  equal  volume  of  sodium  hydroxide  and  a  few  grains 
of  bismuth  subnitrate.  Mix  well  and  boil  for  several  minutes. 


URINE  ANALYSIS.  109 

In  presence  of  glucose,  black  metallic  bismuth  will  be  precipitated. 
A  rather  more  delicate  reaction  is  obtained  by  using  the  ALMEN- 
BOTTGER  TEST  (Nylander's).  Ten  c.c.  of  urine  are  boiled  with  1 
c.c.  of  Almen's  reagent  (see  Appendix);  black  metallic  bismuth 
is  separated. 

Precautions. — Albumin,  if  present,  will  cause  the  precipitation 
of  black  bismuth  sulphide.  Many  normal  urines  will  cause  a 
slight  darkening  of  the  bismuth  subnitrate,  such  as  might  be  pro- 
duced by  a  trace  of  sugar. 

PHENYL-HYDRAZIN  TEST.  To  50  c.c.  of  urine  add  2  grammes 
of  phenyl-hydrazin  hydrochloride,  and  4  grammes  of  sodium 
acetate.  Dissolve  the  reagents  in  the  urine  and  heat  on  the  water 
bath  for  one  hour.  In  presence  of  glucose  fine  yellow  crystalline 
needles  of  glucosazone  separate  out  on  cooling. 

Precaution*. — A  similar  precipitate  is  given  by  other  carbohy- 
drates, and  under  certain  circumstances  by  glycuronic  acid.  It 
may  be  necessary  to  examine  the  precipitate  microscopically  for 
the  characteristic  crystals,  or  even  to  determine  their  melting  point 
(204°-205°  C.)  in  order  to  positively  identify  them. 

FERMENTATION  TEST.  (See  p.  70. )  This  test  is  useful  in  iden- 
tifying glucose  in  presence  of  other  reducing  substances,  as,  for  in- 
stance, in  distinguishing  glucose  in  presence  of  glycuronic  acid.  It 
is  not,  however,  to  be  relied  upon  when  but  a  small  amount  of 
glucose  is  present. 

INDIGO-CARMINE  TEST.  (See  p.  70.)  This  is  an  exceedingly 
delicate  test,  but  gives  a  faint  reaction  with  nearly  all  urines. 

ALPHA-NAPHTHOL  TEST.  (See  p.  71.)  A  delicate  test  and 
often  recommended,  but,  like  the  last  test  named,  it  is  given  by 
nearly  all  urines. 

QUANTITATIVE  DETERMINATION.  By  Fehling's  Solution. — Ten  c.c. 
of  Fehling's  solution  (see  Appendix)  are  measured  into  a  porce- 
lain dish  with  30  to  40  c.c.  of  water.  The  diluted  solution  is 
heated  to  boiling  and  the  urine  added  from  a  burette  until  the  blue 
color  of  the  Fehling's  solution  has  entirely  disappeared.  Note  the 
number  of  c.c.  of  urine  required  to  produce  this  result,  and  calcu- 
late the  amount  of  glucose  present,  by  the  formula  -*.  =  P,  in 
which  U  represents  the  number  of  c.c.  of  urine  added  to  produce 
complete  decomposition,  and  P  equals  the  percentage  of  glucose 
in  the  sample.  From  this  the  amount  passed  in  the  24  hours 
urine  can  be  calculated.  When  considerable  sugar  is  present,  it  is 


1 10  URINE  ANALYSIS. 

well  to  dilute  the  urine  with  a  known  volume  of  water,  to  deter- 
mine the  glucose  in  the  diluted  sample,  and  then  to  calculate  back 
to  the  original. 

By  Purdy's  Ammoniacal  Copper  Solution. — Dilute  the  urine  with 
two  or  three  volumes  of  water  carefully  measured.  Place  35  c.c. 
of  the  test  solution  (see  Appendix)  in  a  200  c.c.  flask,  add  about 
70  c.c.  of  water,  boil,  and  from  a  burette,  add  the  diluted  urine 
until  the  blue  color  of  the  solution  is  just  destroyed.  The  35  c.c. 
of  Purdy's  solution  are  decolorized  by  0.02  gramme  of  glucose. 
From  the  number  of  c.c.  of  urine  required  to  produce  the  result, 
calculate  the  amount  of  glucose  present,  first  in  the  diluted  and 
then  in  the  undiluted  urine. 

Pavy's  ammoniacal  copper  test  is  very  similar  to  the  above,  and 
is  sufficiently  described  in  the  Appendix.  Purdy's  method  is  a 
highly  satisfactory  one  for  clinical  purposes,  though,  in  skilled 
hands,  Fehling's  is  unsurpassed.  The  fermentation  processes, 
which  follow,  are  not  to  be  recommended  unless  reducing  sub- 
stances other  than  glucose  are  known  to  be  present.  Approximate 
results  only  are  obtained. 

Roberts'  Fermentation  Method. — After  a  careful  determination  of 
its  specific  gravity  (to  the  third  decimal),  the  urine,  together  with 
a  small  piece  of  compressed  yeast,  is  placed  in  a  loosely-stoppered 
flask  and  left  for  24  hours.  The  alcohol  and  carbonic  anhydride 
produced  by  the  fermentation,  reduce  the  specific  gravity  of  the 
solution  one  degree  for  each  grain  of  sugar  per  fluid  ounce.  At 
the  end  of  the  operation  the  specific  gravity  is  again  determined, 
the  loss  representing  the  number  of  grains  of  sugar  per  fluid  ounce. 
This  number  multiplied  by  0. 23  gives  the  percentage  of  glucose  in 
the  sample.  It  is  well  to  make  a  parallel  test  on  a  sample  with- 
out sugar,  observing  any  variation  that  may  occur  in  its  specific 
gravity. 

Einhorri1 s  Method. — Ten  c.c.  of  the  urine  are  shaken  with  about 
1  gramme  of  compressed  yeast,  and  the  mixture  introduced  into 
Einhorn's  apparatus,  a  small  graduated  tube  of  special  form. 
The  carbonic  anhydride  gas  evolved  is  measured  at  the  end  of  24 
hours,  its  volume  expressing  directly,  by  the  graduations  on  the 
tube,  the  percentage  of  glucose  present. 

UREA,  CO(NH2)2. 
The  urea  varies  in  normal  urine  from  20  to  40  grammes  (309  to 


B,  0 


o 


URINE  ANAL YSIS.  1 1 1 

617  grains)  in  the  24  hours,  with  an  average  for  men  of  about  34 
grammes*  (535  grains).  It  is  to  be  noted  that  this  average  is  for 
an  adult  male  under  forty  years  of  age.  Age,  sex  and  conditions 
must  be  considered  in  deciding  upon  a  normal  average  for  each 
individual  under  examination.  For  variations  from  normal  con- 
ditions deductions  may  be  made  in  the  proportions  given  under 
the  total  solids,  page  104.  Women  secrete  less  than  men,  children 
absolutely  less,  but  relatively,  i.  e.,  in  proportion  to  body  weight, 
more.  The  urea  is  increased  by  a  nitrogenous  diet,  by  mental  and, 
possibly,  physical  activity,  at  the  beginning  of  the  crisis  in  fevers, 
in  ague,  in  diabetes,  in  pleurisy,  and  in  acute  tuberculosis.  The 
urea  is  decreased  by  profuse  perspiration,  by  diarrhoea,  in  cholera, 
in  all  forms  of  Bright' s  disease,  in  diabetic  coma,  in  anaemia,  and 
generally,  in  most  chronic  debilitating  disorders.  Expressing,  as 
it  does,  the  progress  of  nitrogenous  metabolism  in  the  body,  the 
determination  of  the  urea  passed  is  important. 

Approximate  Estimation. — When  the  chlorides  are  normal  and 
when  sugar  and  albumin  are  absent,  the  urea  may  be  taken  as 
one-half  the  total  solids. 

Hypobromite  Method. — There  are  several  applications  of  this 
method,  depending  on  differences  in  the  form  of  apparatus  used; 
the  principle  is  the  same,  however,  in  all.  A  solution  of  sodium 
hypobromite  containing  an  excess  of  sodium  hydroxide  (see  Ap- 
pendix) is  added  to  the  urine;  the  urea  is  decomposed,  nitrogen 
gas  is  set  free,  and  sodium  bromide  and  carbonate  are  formed. 

CO(NH2)2+3NaBrOi2NaOH  =  3NaBr  +  Na2C03  +  N2  4-3H2O. 

The  nitrogen  evolved  is  measured  and,  from  its  volume,  the  per- 
centage of  urea  calculated. 

A  solution  of  chlorinated  soda  with  potassium  bromide  may  be 
used  in  place  of  the  alkaline  hypobromite,  thus  avoiding  the 
rather  offensive  fumes  of  bromine.  (See  Appendix  for  the  solution. ) 

Twenty  c.c.  of  fresh  hypobromite  solution  (40  c.c.  of  the  chlor- 
inated soda)  are  placed  in  a  bottle,  and  the  measured  urine,  con- 
tained in  a  small  test-tube,  is  introduced  in  such  a  manner  that 
the  tube  will  stand  in  the  bottle  without  spilling.  The  bottle  is 
then  connected  by  means  of  a  perforated  stopper  and  rubber  tube 
with  the  to})  of  an  inverted  burette  standing  in  a  jar  of  water.  All 

*  Dr.  Clifford  Mitchell,  of  Chicago,  considers  this  average  high.  As  a  result  of 
his  analyses  he  gives,  for  men,  26.5  grammes,  for  women  20.5. 


112  URINE  ANAL  YSIS. 

connections  are  carefully  made,  and  the  volume  of  air  in  the  bu- 
rette read  from  the  graduations.  The  urine  is  now  slowly  mixed 
with  the  hypobromite,  nitrogen  gas  is  evolved,  and  a  correspond- 
ing volume  of  air  is  driven  from  the  bottle,  displacing  the  water  in 
the  burette.  When  the  evolution  of  gas  has  ceased,  let  the  appar- 
atus stand  for  a  few  minutes,  and  then  measure  again  the  air  in 
the  burette.  The  increase  in  volume  represents  the  volume  of 
nitrogen  given  off.  The  observed  increase,  in  c.c.,  multiplied  by 
the  factor  0.0027,  gives  the  weignt  in  grammes  of  urea  in  the 
sample  taken;  e.  g.,  if  4  c.c.  of  urine  were  used  for  the  test,  and 
21  c.c.  of  nitrogen  were  evolved,  then  we  have,  0.0027X21  = 
0.0567  gramme  of  urea  in  4  c.c.  of  urine,  or,  1.42  per  cent. 
(0. 0567-4  X  100). 

Theoretically  the  factor  employed  should  be  0.00268,  but  as  the 
theoretical  volume  of  nitrogen  is  not  given  off,  0.0027  gives  more 
accurate  results.  In  reading  the  volume  of  gas  in  the  burette  it  is 
of  course  necessary  that  the  latter  shall  be  raised  or  lowered  so  as 
to  bring  the  water  on  the  same  level  inside  and  out. 

The  Ureameter  devised  by  Prof.  Doremus,  of  N.  Y.,  is  conveni- 
ent, and  in  its  latest  form,  with  a  side  tube  for  accurate  delivery 
of  the  urine  replacing  the  pipette  formerly  used,  it  yields  excellent 
results.  The  long  arm  of  the  instrument  is  nearly  filled  with  the 
alkaline  solution  of  sodium  hypobromite,  water  is  added  to  cut  off 
the  elbow  leading  from  the  bulb,  and  then  one  c.c.  of  urine  is 
carefully  introduced  at  the  foot  of  the  long  arm.  The  percentage 
of  urea  is  read  directly  from  the  graduations  on  the  tube. 

URIC  ACID,  H2C5H2N4O3,  AND  URATES. 

Uric  acid,  averaging  from  0.3  to  0.8  gramme,  is  normally  pres- 
ent in  the  urine  in  combination,  as  a  urate.  It  is  increased  in 
pneumonia,  indigestion,  acute  rheumatism,  in  leucocytbsemia,  by 
excessive  meat  diet,  by  lack  of  exercise,  and  in  disorders  of  the 
circulation  and  respiration.  It  is  decreased  in  most  chronic  dis- 
eases, in  the  later  stages  of  Bright' s  disease,  in  diabetes,  in  gouty 
affections,  and  in  chronic  rheumatism.-  It  is  to  be  remembered 
that  the  appearance  of  a  deposit  of  uric  acid,  or  of  urates,  does  not 
necessarily  point  to  an  excess  of  these  ingredients.  High  acidity 
of  the  urine,  and  a  decrease  in  mineral  salts,  tend  to  produce  a 
separation  of  uric  acid  equally  with  the  presence  of  an  increase  of 
that  substance.  The  deposits  are  easily  recognized.  (See  under 
Urinary  Sediments. ) 


URINE  ANAL  YSIS.  113 

Uric  acid  may  be  separated  from  the  urine  as  follows:  To  200 
c.c.  of  urine  add  20  c.c.  of  strong  hydrochloric  acid  and  let  the 
mixture  stand  48  hours.  Collect  the  sediment  on  a  previously 
weighed  filter  paper,  wash  with  cold  water,  dry  and  weigh.  The 
increase  in  weight  represents  uric  acid. 

To  detect  uric  acid  or  urates  apply  the  Murexid  Test.  Evaporate 
the  sediment  with  a  drop  of  nitric  acid.  A  yellow  residue  is  ob- 
tained, which,  when  moistened  with  a  drop  of  ammonium  hydrox- 
ide, turns  to  a  purple-red. 

Determination  of  Uric  Acid.  Hartley's  Method. — To  50  c.c.  of 
clear  urine  add  5  c.c.  of  magnesium  mixture  (see  Appendix)  and 
about  10  c.c.  of  ammonia,  Sp.  Gr.  0.96.  Warm  and  add,  from  a 
burette,  a  fiftieth-normal  solution  of  silver  nitrate.  From  time  to 
time  remove  a  drop  of  the  solution  and  test  on  a  porcelain  plate 
with  a  weak  solution  of  sodium  hydrogen  sulphide.  The  appear- 
ance of  a  dark  cloud  indicates  the  end  reaction.  Deduct  0.5  c.c. 
from  the  amount  of  silver  nitrate  used  and  multiply  the  remainder 
by  0.00336  (the  equivalent  of  each  c.c.  of  fiftieth-normal  silver 
nitrate  in  terms  of  uric  acid).  From  the  result,  the  amount  of 
uric  acid  in  the  sample,  the  percentage  may  be  easily  calculated. 

Hopkin's  Method. — Saturate  the  urine  with  crystalline  ammonium 
chloride,  filter  off  the  precipitated  amoniurn  urate,  wash  with  a 
saturated  solution  of  ammonium  chloride,  dissolve  in  weak  alkali, 
neutralize  with  hydrochloric  acid,  and  collect  the  uric  acid  on  a 
weighed  filter. 

CHLORIDES. 

The  chlorine  of  the  24  hours  urine  varies  from  6  to  10  grammes, 
equivalent  to  10  to  16  grammes  of  sodium  chloride.  The  average 
for  an  adult  man  may  be  placed  at  7  grammes  chlorine  (11.5 
grammes  sodium  chloride),  for  women,  at  6  grammes  chlorine, 
and  for  children,  about  5  grammes  chlorine.  The  amount  varies 
during  the  day,  being  increased  several  hours  after  a  full  meal,  and 
by  mental  or  physical  labor.  It  is  diminished,  in  most  fevers  (in- 
creasing again  just  before  or  just  after  the  crisis),  in  pneumonia, 
pleurisy,  typhoid,  cholera,  and  in  many  chronic  diseases. 

Approximate  Estimation. — To  the  urine  in  a  test-tube  add  a  few 
drops  of  dilute  nitric  acid  and  2-3  drops  of  a  10  p.  c.  solution  of 
silver  nitrate.  If  the  chlorides  be  high  or  normal,  a  curdy  white 
precipitate  is  formed;  if  low,  only  a  milky  cloudiness. 


114 


URINE  ANALYSIS. 


Accurate  Determination. — The  general  method  of  chlorides  (p.  64) 
may  be  applied  to  the  urine,  using  a  10  c.c.  sample  and  diluting 
with  water.  The  number  of  c.c.  of  deci-normal  silver  nitrate  used 
multiplied  by  0.003537,  will  give  the  weight  of  chlorine  in  the 
sample,  and  from  this  the  percentage  may  be  calculated.  Should 
it  be  desirable  to  report  in  terms  of  sodium  chloride,  multiply  by 
0.005837  instead  of  by  0.003537.  In  the  application  of  this  test 
to  the  urine  there  are,  however,  unavoidable  errors,  and  the  follow- 
ing—  Volhard's  Method,  is  preferred.  The  solutions  required  are, 
in  addition  to  the  Deci-normal  Silver  Nitrate,  Ferric-Ammonium 
Sulphate  (Ferric-Alum) — 10  grammes  dissolved  in  100  c.c.  of 
water,  and,  Deci-normal  Potassium  Sulphocyanate  Solution — Dis- 
solve 10  grammes  of  potassium  sulphocyanate  in  one  litre  of  water. 
Introduce  into  a  flask  10  c.c.  of  deci-normal  silver  nitrate,  0.5  c.c. 
of  ferric-alum  solution,  and  5  c.c.  dilute  nitric  acid.  Add  the 
sulphocyanate  from  a  burette  until  there  is  produced  a  faint 
brownish-red  color  which  does  not  disappear  on  shaking.  Note 
the  number  of  c.c.  of  sulphocyanate  used,  and  then  dilute  the  re- 
mainder until  one  c.c.  is  exactly  equivalent  to  one  c.c.  of  deci- 
normal  silver  nitrate. 

The  process  of  analysis  is  then  as  follows:  In  a  150  c.c.  rlask 
place  3.537  grammes  (about  3.4  c.c.)  of  urine,  3  c.c.  nitric  acid, 
and  20  c.c.  water.  Add  10  c.c.  deci-normal  silver  nitrate,  exactly 
measured,  and  shake  the  mixture.  Add  0.5  c.c.  ferric-alum  solu- 
tion, and  then,  from  a  burette,  the  deci-normal  sulphocyanate 
until  the  appearance  of  a  faint,  permanent,  brownish-red  colora- 
tion indicates  the  end  of  the  reaction.  Subtracting  the  number  of 
c.c.  of  potassium  sulphocyanate  added  from  the  10  c.c.  of  silver 
nitrate  used,  we  ascertain  the  amount  of  silver  nitrate  required  to 
precipitate  the  chlorides  of  the  sample.  Each  c.c.  so  required 
represents  0.10  per  cent,  of  chlorine  in  the  urine. 

For  sodium  chloride,  multiply  the  chlorine  found  by  1.65,  or 
modify  the  above  test,  using  5.837  grammes  (about  5.7  c.c. )  of 
urine  and  15  c.c.  of  silver  nitrate.  Each  c.c.  of  decinormal  silver 
nitrate  then  required  for  the  precipitation  corresponds  to  0. 10  per 
cent,  of  sodium  chloride. 

SULPHATES. 

Sulphuric  acid  is  found  in  the  urine  combined  with  both  organic 
and  inorganic  bases,  the  latter  combination  being  normally  in 


URINE  ANAL  YSIS.  115 

excess  of  the  former.  Calculated  to  sulphur  trioxide,  the  sul- 
phates vary  in  normal  urine  from  1.5  to  3  grammes  daily,  with  an 
average  of  ahout  2.2  grammes.  The  sulphates  are  increased  by 
animal  food,  by  physical  activity,  by  ingestion  of  sulphur  com- 
pounds, in  acute  inflammatory  diseases,  pneumonia,  acute  rheu- 
matism, delirium,  and  often  in  diabetes  insipidus.  They  are 
decreased,  with  diminished  metabolism  in  chronic  affections,  in 
leucsemia,  and  in  diabetes  mellitus. 

Approximate  Estimation. — Add  to  the  urine  a  few  drops  of  dilute 
hydrochloric  acid  and  one-fourth  volume  of  barium  chloride.  An 
opaque  milky  cloudiness  indicates  normal  sulphates;  an  opaque 
creamy  precipitate,  increased  sulphates;  a  faint  semi-transparent 
cloudiness,  diminished  sulphates. 

SULPHATES  OF  ORGANIC  BASES.  Sulphates  of  phenol,  cresol, 
pyrocatechol,  indol,  skatol,  etc.  These  compounds  are  derived 
partially  from  the  food,  but  are  interesting  chiefly  as  putrefaction 
products  absorbed  from  the  intestine.  In  normal  urine  they  are 
present  in  small  amount,  probably  about  10  per  cent,  of  the  total 
sulphates,  but  in  certain  stomach  troubles,  in  disordered  absorp- 
tion, and  from  abnormal  fermentative  and  putrefactive  changes, 
they  may  be  considerably  increased. 

Determination  of  Organic  Sulphates. — 100  c.c.  of  the  urine  are 
mixed  with  100  c.c.  of  Barium  Mixture  (see  Appendix),  and  the 
precipitate  formed  filtered  off.  An  aliquot  part  of  the  filtrate  is 
acidified  with  hydrochloric  acid  and  boiled.  It  is  then  heated  to 
100°  C.  for  an  hour,  allowed  to  stand  until  completely  settled,  and 
finally  filtered  through  an  ashless  paper.  The  precipitate  is  dried, 
ignited  and  weighed.  The  weight  of  barium  sulphate  found  multi- 
plied by  0.34335  gives  its  equivalent  in  terms  of  sulphuric  an- 
hydride. 

The  Total  Sulphates  may  be  determined  by  acidifying  the  urine 
with  hydrochloric  acid,  boiling,  and  adding  barium  chloride  until 
all  is  precipitated.  The  precipitate  is  then  treated  as  described 
above. 

PHOSPHATES. 

The  phosphates  of  the  urine  may  be  divided  into  two  classes, 
the  alkaline  phosphates,  phosphates  of  sodium  and  potassium  (f); 
the  earthy  phosphates,  phosphates  of  calcium  and  magnesium  (J). 
The  latter  are  subject  to  but  little  variation  in  disease.  The  total 


116  URINE  ANAL  YSIS. 

phosphates  calculated  as  phosphorus  pentoxide,  vary  in  normal 
urine  from '2. 5  to  3.5  grammes,  with  a  daily  average  of  3  grammes. 
They  are  increased  in  acute  inflammatory  diseases,  in  the  early 
stages  of  acute  fevers,  in  phthisis,  leucaemia,  osteornalacia,  and 
sometimes  in  diabetes.  They  are  decreased,  in  many  chronic  brain 
troubles,  in  epilepsy,  general  paralysis,  melancholia,  etc.,  in 
chronic  interstitial  nephritis,  in  chlorosis,  gout,  and  chronic  rheu- 
matism. 

lotal  Phosphates. — Add  to  the  urine  magnesia  mixture  (see 
Appendix)  and  ammonia.  The  total  phosphates  are  precipitated, 
and  can  be  compared  with  a  corresponding  precipitate  from  a 
normal  urine. 

Earthy  Phosphates — Approximate  Estimation. — Place  2  inches  of 
urine  in  a  6-inch  test-tube,  add  a  few  drops  of  sodium  hydroxide 
and  heat  to  boiling.  Set  aside  for  15  minutes  to  allow  the  precipi- 
tate to  settle,  If  the  phosphates  be  normal  the  precipitate  will 
occupy  about  J  inch  at  the  bottom  of  the  tube;  if  high,  1  inch  or 
more;  if  low,  less  than  J  inch. 

Alkaline  Phosphates. — Appxoximate  Estimation. — Add  a  little  am- 
monium hydroxide  to  the  urine,  filter  off  the  precipitated  earthy 
phosphates,  and  to  the  filtrate  add  J  volume  of  magnesia  mixture. 
A  semi-opaque  cloudiness  on  shaking  indicates  normal  phosphates; 
a  creamy  appearance,  increased  phosphates;  a  slight  cloudiness, 
decreased  phosphates. 

Accurate  Determination  of  Total  Phosphates. — Solutions. — Standard 
Uranium  Nitrate: — Dissolve  35.5  grammes  of  uranium  nitrate  in  a 
mixture  of  25  c.c.  strong  acetic  acid  with  800  c.c.  of  water.  Dilute 
with  water  to  1000  c.c.  Each  c.c.  of  this  solution  is  equivalent  to 
0.005  gramme  of  phosphoric  anhydride,  P205. 

Acid  Solution  of  Sodium  Acetate: — Dissolve  10  grammes  of 
sodium  acetate  in  90  c.c.  of  water  and  add  10  c.c.  of  strong  acetic 
acid. 

Potassium  Ferrocyanide: — One  gramme  dissolved  in  120  c.c.  of 
water. 

Method. — To  50  c.c.  of  urine  add  about  10  c.c.  of  the  sodium 
acetate  solution  and  warm  the  mixture  to  80°  C.  Maintain  at  this 
temperature,  and,  from  a  burette,  add  the  standard  uranium 
nitrate,  testing  from  time  to  time  until  a  drop  of  the  mixture 
develops  a  brown  clolor  when  touched  with  a  drop  of  potassium 
ferrocyanide.  The  number  of  c.c.  of  uranium  nitrate  used,  mul- 


URINE  ANAL YSIS.  1 17 

tiplied    by  0.005,   gives   the  weight   in   grammes   of   phosphoric 
anhydride  in  the  50  c.c.  of  urine. 

INDICAN. 

Indican,  or,  properly,  potassium  indoxyl-sulphate,  C8H6- 
NKS04,  is  derived  from  the  indole,  C8H7N?  of  the  intestine. 
Normally  present  in  small  amount,  it  becomes  greatly  increased 
in  certain  intestinal  disorders  from  absorption  of  decomposition 
products.  It  is  increased  generally  in  cancer  of  the  liver,  in  cer- 
tain suppurative  diseases,  by  intestinal  obstruction,  by  peritonitis, 
and  by  administration  of  many  aromatic  drugs,  creosote,  turpen- 
tine, etc. 

To  5  c.c.  concentrated  hydrochloric  acid  add  20-30  drops  of 
urine  and  warm,  but  do  not  boil,  the  mixture.  With  normal 
urine  the  resulting  color  will  be  yellow  or  a  very  pale  violet,  while 
with  increased  indican  a  darker  violet  or  blue  will  be  obtained. 
Add  2  drops  of  nitric  acid  and  warm  gently.  There  may  be  a 
slight  increase  in  color  at  first,  but  this  will  be  followed  by  the  dis- 
appearance, of  the  blue  tint — more  or  less  rapidly,  according  as  to 
whether  little  or  much  indican  be  present. 

BILE. 

Bile  constituents  may  occasionally  appear  in  the  urine  of  healthy 
persons,  particularly  during  the  heat  of  summer,  but  as  a  rule 
their  presence  is  characteristic  of  the  condition  known  as  jaundice. 
Bile  pigments  and  bile  acids  may  both  be  present,  but  the  clinical 
examination  is  practically  limited  to  the  former.  The  urine  ^'s 
generally  yellowish-brown  to  green,  sometimes  almost  black,  and 
yields  a  characteristic  yellow  froth  on  shaking.  It  must  be  re- 
membered, however,  that  certain  drugs  may  produce  a  similar 
appearance. 

TESTS  FOR  BILE  PIGMENTS.  MarechaVs  Test. — Float  a  few  drops 
of  tincture  of  iodine  on  the  surface  of  the  urine  in  a  test-tube.  In 
presence  of  bile  pigments,  a  green  coloration  appears  below  the  red 
iodine  layer. 

Gmelin's  Test. — The  urine  is  floated  over  yellow  nitric  acid  in  a 
test-tube.  A  succession  of  colors,  green,  blue,  violet  and  red,  will 
appear  at  the  contact  of  the  two  liquids. 

In  Rosenbach's  modification  of  this  test  the  urine  is  filtered 
through  a  thick  paper.  A  drop  of  yellow  nitric  acid  applied  to  the 


1 1 8  URINE  ANAL  YSIS. 

inside  of  the  dried  filter  will  produce  a  yellow  spot  surrounded  by 
yellowish-red,  violet,  blue  and  green  rings. 

Huppert's  Test. — The  urine  is  treated  with  lime  water,  or  with  a 
solution  of  calcium  chloride  followed  by  ammonium  carbonate; 
the  precipitate  is  filtered  off,  thoroughly  washed,  and  then  trans- 
ferred to  a  test-tube.  A  little  acetic  acid  is  now  added,  then  chlor- 
oform. On  shaking,  the  acetic  acid  will  be  colored  green,  while 
the  chloroform  will  show  a  yellow  or  a  green  tint  according  to  the 
relative  amounts  of  bilirubin  and  biliverdin  present. 

TEST  FOR  BILE  ACIDS.  Pettenkofcr' s  Test. — Evaporate  about  200 
c.c.  of  urine  to  dryness,  extract  the  residue  with  absolute  alcohol, 
filter,  evaporate  the  alcoholic  filtrate,  and  dissolve  the  second 
residue  in  a  little  water.  Add  a  few  drops  of  a  concentrated  solu- 
tion of  cane  sugar,  and  a  drop  of  sulphuric  acid,  then  warm  the 
mixture  in  a  capsule.  A  purple  or  cherry-red  color  indicates  the 
presence  of  bile  acids. 

Instead  of  evaporating  the  alcoholic  filtrate,  the  bile  acids  may 
be  precipitated  from  that  solution  by  an  excess  of  ether,  the  pre- 
cipitate separated,  and  dissolved  in  water.  The  water  solution  in 
either  case  will  probably  need  to  be  decolorized  by  animal  char- 
coal, before  applying  the  color  test. 

The  test  may  be  clinically  modified  as  follows:  To  the  urine, 
which  must  be  albumin-free,  add  a  little  sugar  syrup  and  then  dip 
into  the  mixture  a  strip  of  filter  paper.  Dry  the  paper  and  touch 
it  with  a  drop  of  sulphuric  acid.  Bile  acids  being  present,  a 
purple  spot  tiiay  be  obtained. 

For  other  modifications  of  the  bile  tests,  see  Index. 

BLOOD. 

Blood  in  the  urine  may  be  derived  from  the  kidneys,  in  cancer, 
acute  nephritis,  after  powerful  diuretics,  etc. ;  from  the  bladder,  in 
diphtheritic  and  acute  cystitis,  calculi,  carcinoma,  congestion,  etc. ; 
from  structural  disease  of  the  prostate,  and  from  mechanical  in- 
jury. When  uniformly  mixed  with  the  urine  the  blood  is  prob- 
ably from  the  kidneys,  though  possibly  from  the  prostate;  when 
stringy  or  in  clots,  it  is  more  likely  to  be  from  the  bladder  or 
urethra  Unless  in  considerable  amount,  its  recognition  is  best 
effected  by  microscopic  examination  of  the  sediment,  or  by  spec- 
trum analysis.  As  regards  the  microscopic  examination,  however, 
it  is  to  be  remembered  that  blood  pigment  may  be  present  when 


URINE  ANAL  YSIS.  j  j  9 

blood  corpuscles  are  entirely  absent,  When  the  amount  of  blood 
is  large  the  urine  will  be  dark-red  or  brown,  often  "smoky"  in 
appearance,  and  the  precipitate  of  earthy  phosphates  with  sodium 
hydroxide  (Heller's  Test  for  blood)  will  be  reddish  instead  of  white. 
Should  the  urine  be  alkaline  and  the  phosphates  already  precipi- 
tated, add  an  equal  volume  of  normal  acid  urine  and  a  few  drops 
of  barium  chloride  before  boiling  with  sodium  hydroxide.  Haemo- 
globin may  be  detected  by  the  Guaiacum  Test. — To  the  urine  in  a 
test-tube  add  3-4  drops  of  a  freshly  prepared  tincture  of  guaiacum 
and  mix  by  shaking.  Float  on  the  surface  of  a  mixture  a  little 
etherial  solution  of  hydrogen  dioxide  ("ozonic  ether")  and  let  it 
stand  without  shaking.  In  presence  of  ha?rnoglobin  (and  of  some 
other  substances)  a  blue  color  will  develop  in  the  etherial  layer  at 
the  contact  between  the  two  liquids. 

Lecartau's  Test  may  be  used  for  the  detection  of  haBmatin.  The 
urine  is  acidulated  with  acetic  acid  and  boiled.  The  brown  coag- 
ulum  is  separated,  washed  with  water,  and  shaken  with  alcohol 
which  has  been  acidulated  with  sulphuric  acid.  The  reddish- 
brown  solution  is  filtered  and  the  filtrate  examined  spectroscop- 
ically.  A  part  of  the  same  filtrate  may  be  evaporated  to  dryness 
and  the  residue  tested  for  iron. 

Hcemin  Test. — Place  a  few  drops  of  the  urine  on  a  glass  slide  and 
add  a  drop  or  so  of  glacial  acetic  acid.  Heat  cautiously  until 
bubbles  appear.  On  cooling  there  will  separate  out  dark  brown 
triclinic  plates  and  prisms  of  "ha?min,"  the  hydrochloride  of 
hrcmatin. 

See  also  under  Blood,  p.  97. 

OTHER  ABNORMAL  INGREDIENTS. 

Scrum- Globulin. — This  resembles  serum-albumin  and  generally 
accompanies  it  in  the  urine.  It  is  insoluble  in  water  and  may  be 
detected  by  dropping  the  urine  slowly  into  a  beaker  of  clear  water, 
each  drop  as  it  falls  producing  a  slight  cloud.  Serum-globulin 
responds  to  most  of  the  albumin  tests.  To  separate  globulins  and 
albumins,  saturate  the  urine  with  magnesium  sulphate;  the  globu- 
lins are  precipitated  and  can  be  filtered  off.  Test  the  filtrate  for 
albumin. 

Albumose. — Tested  for  in  presence  of  other  proteids,  as  follows: 
Saturate  the  urine  with  sodium  chloride,  acidify  with  acetic  acid, 
boil,  and  filter  while  hot.  The  albumose  separates  from  the  fil- 


1 20  URINE  ANAL  TSIS. 

trate  on  cooling;  dissolve  in  water  and  apply  the  nitric  acid  test. 
Albumose  precipitated  by  nitric  acid,  dissolves  on  heating,  and  is 
reprecipitated  on  cooling. 

Peptones. — Peptones  may  appear  in  the  urine  in  acute  rheuma- 
tism, in  suppurative.  diseases,  in  cancer  of  the  liver  and  intestines, 
in  croupous  pneumonia,  typhoid,  scarlet  fever,  small-pox,  and  in 
tuberculosis.  Deutero-albumose  is,  however,  often  mistaken  for 
peptone.  In  presence  of  other  proteids,  acidify  with  acetic  acid, 
add  ammonium  sulphate  to  saturation,  filter  and  examine  the  fil- 
trate for  peptones  by  the  xantho-proteic  test  and  by  precipitation 
with  picric  acid.  Show  the  absence  of  other  proteids  by  the  nitric 
acid  contact  test. 

Acetone,  (CH3)2CO. — Normally  present  in  minute  amount,  is 
increased  in  febrile  conditions,  in  the  later  stages  of  diabetes  melli- 
tus,  and,  frequently,  after  profound  narcosis.  It  may  be  tested 
for  in  the  urine  directly,  or  after  distillation  of  the  urine  with  phos- 
phoric acid.  LegaVs  Test. — To  5  c.c.  of  the  urine  (or  to  25  c.c.  of 
the  distillate)  add  sufficient  sodium  hydroxide  to  give  a  decided 
alkaline  reaction,  and  then  add  a  few  drops  of  a  fresh  aqueous 
solution  of  sodium  nitroprusside.  The  mixture  assumes  a  ruby- 
red  color.  Acidify  the  solution  with  glacial  acetic  acid,  a  purple- 
red  color  indicates  the  presence  of  acetone.  Chaiitard's  Test. — A 
drop  of  an  aqueous  solution  of  magenta,  previously  decolorized  by 
sulphurous  acid,  added  to  the  distillate,  develops  a  rich  violet 
color. 

Acetylacetic  Acid,  C2H3OCH2C02H,  commonly  called  Diacetic 
Acid,  or  its  ethyl  ether  compound,  is  related  to  acetone  in  its  oc- 
currence, and  is  possibly  an  intermediate  step  in  the  formation  of 
acetone.  Its  appearance  in  the  urine  of  a  diabetic  is  to  be  consid- 
ered of  grave  import.  Diacetic  acid  may  be  tested  for  as  follows: 
To  the  fresh  urine  add  a  few  drops  of  a  neutral  solution  of  ferric 
chloride.  Filter  off  any  precipitated  phosphate,  and  to  the  filtrate 
add  two  drops  more  of  the  iron  salt.  A  Bordeaux-red  color  being 
produced,  diacetic  acid  may  be  present.  Repeat  the  test,  using  a 
boiled  portion  of  the  urine;  little  or  no  color  will  now  be  developed 
if  the  color  of  the  first  test  were  due  to  the  acid.  As  a  further  test 
a  portion  of  the  urine  is  acidulated  with  sulphuric  acid  and  ex- 
tracted with  ether.  Apply  the  iron  test  to  the  etherial  extract.  If 
the  color  produced  fade  in  24-48  hours,  it  is  probably  due  to  dia- 
cetic acid;  if  it  does  not  fade,  it  may  be  due  to  hydroxybutyric 
acid. 


URINE  ANALYSIS.  121 

Hydroxybutyric  acid,  C4H803,  is  closely  related  to  acetone  and 
diacetic  acid  and  often  occurs  with  them  in  the  urine.  It  is  found 
in  the  later  stage  of  diabetes,  in  cachexia,  also  sometimes  in  scarlet 
fever,  measles,  etc.  It  responds  to  the  ferric  chloride  test  for  dia- 
cetic acid. 

Glycuronic  Acid,  C6H1007.  —  Occurs  in  normal  urine  in  traces, 
but  is  much  increased  by  ingestion  of  chloral,  nitrobenzole,  cam- 
phor, morphine,  etc.,  and  particularly  after  a  profound  chloroform 
narcosis.  It  is  of  importance  because  of  its  resemblance  to  glucose, 
responding  to  several  of  the  principal  glucose  tests.  It  does  not, 
however,  respond  to  the  fermentation  test  with  yeast,  and  unless 
present  in  large  amount  gives  no  reaction  with  phenylhydrazin, 
provided  this  test  be  performed  exactly  as  described  on  page  109. 
With  insufficient  heating  of  the  mixture  crystals  are  obtained, 
melting  at  150°  C. 

In  common  with  pentose,  glycuronic  acid  gives  the  following  test: 
Decolorize  the  urine  with  charcoal  and  add  0.5  c.c.  to  5-6  c.c.  of  a 
saturated  solution  of  phloroglucin  in  strong  hydrochloric  acid. 
Upon  warming  a  purple-red  color  is  developed. 

Pus. — Pus  in  the  urine  may  be  from  renal  abscess,  from  inflam- 
mation or  cancer  of  the  bladder,  from  suppuration  in  the  prostate 
or  urethra,  etc.  When  the  pus  originates  in  the  bladder  the  urine 
is  generally  alkaline;  when  from  the  kidneys,  the  urine  is  gener- 
ally acid.  Pus  is  best  recognized  microscopically,  but,  if  in  con- 
siderable amount,  the  following  tests  may  be  applied:  The  whitish 
sediment  always  present  in  a  urine  carrying  pus  is  not  dissolved 
by  heat.  It  is  insoluble  in  dilute  acids,  and — Donne's  Test — with 
sodium  hydroxide  it  forms  a  semi-gelatinous,  ropy  mass.  Hydro- 
gen dioxide  added  to  pus  causes  a  rapid  effervescence. 

Fat. — May  be  due  to  an  excess  of  fatty  food,  or  it  may  occur  in 
fatty  degeneration  of  the  liver,  in  phosphorus  poisoning,  etc. ,  oc- 
casionally in  diabetes  mellitus  and  in  Bright' s  disease.  When  the 
fat  is  present  in  considerable  amount  the  urine  will  be  more  or  less 
milky  in  appearance  and,  on  standing,  the  fat  globules  will  rise  to 
the  surface.  The  fat  may  be  extracted  from  such  a  sample  by 
agitation  with  ether.  When  present  in  small  amount  the  fat 
globules,  or  fatty  casts,  will  be  recognized  in  the  microscopic  ex- 
amination. 

In  chyluria  all  of  the  chyle  constituents,  fat,  proteids,  etc. ,  are 
present.  Cholesterol  has  been  found  in  chyluria,  and,  also,  in  fatty 


122  URINE  ANALYSIS. 

degeneration  of  the  liver  and,  sometimes,  in  diabetes,  and  in  jaun- 
dice. 

Drugs,  Alkaloids,  etc. — In  irritant  poisoning  the  urine  often  con- 
tains albumin  and  blood.  In  phenol  poisoning,  and  after  inges- 
tion  of  phenol  derivatives,  the  urine  is  dark  colored  and  may 
become  black  on  exposure  to  the  air.  Indican  seems  to  be 
increased  in  the  urine  by  the  ingestion  of  oil  of  bitter  almonds, 
turpentine,  and  creosote.  After  the  ingestion  of  balsams  a  test 
may  be  obtained  with  nitric  acid  resembling  that  given  by  albu- 
min. Santonin,  chrysophanic  acid,  rhubarb,  and  senna,  give  an 
orange-yellow  color.  Asparagus,  turpentine,  cubebs,  and  valerian, 
all  impart  characteristic  odors.  Salicylates  are  excreted  as  sali- 
cylic and  galicyluric  acids.  Glycuronic  acid  is  increased  by  chloral, 
nitrobenzole,  camphor,  and  morphine,  and  after  chloroform  nar- 
cosis. The  ingestion  of  potassium  iodide  causes  the  urine  to  give 
a  greenish-blue  coloration  in  the  guaiacum  test  for  blood.  Qui- 
nine and  antipyrine  darken  the  urine.  Quinine,  atropine,  strych- 
nine, morphine,  and  other  alkaloids  may  be  excreted  in  part 
unchanged.  Sulphonal  may  produce  a  dark  red  urine,  the  color 
being  due  to  hasmatoporphyrin. 

Iodides  and  iodoform  are  tested  for  by  adding  a  little  dilute 
starch  paste  and  then  a  few  drops  of  yellow  nitric  acid;  a  blue  color 
indicates  presence  of  iodine. 

Ehrlich's  "Diazo- Reaction."-—  Two  solutions  are  prepared,  one  a 
saturated  solution  of  sulphanilic  acid  in  50  c.c.  of  hydrochloric 
acid,  diluted  to  1000  c.c.  with  water,  the  other  a  0.5  per  cent, 
solution  of  sodium  nitrite. 

In  applying  the  test  one  part  of  the  nitrite  solution  is  added  to 
50  parts  of  the  sulphanilic  acid  solution,  and  then  one  volume  of 
this  mixture  is  added  slowly  to  an  equal  volume  of  urine.  Am- 
monium hydroxide  is  added  in  slight  excess  and  the  tube  is  well 
shaken.  A  carmine-red  color  appearing  in  the  foam  as  well  as  in 
the  body  of  the  liquid,  constitutes  the  diazo-reaction.  Normal 
urine  shows  an  orange  coloration. 

This  reaction,  it  is  claimed,  is  given  by  the  urine  of  typhoid 
fever  patients  from  the  4th  to  the  7th  day,  continuing,  possibly, 
to  the  22nd  day.  It  is  given,  also,  by  the  urine  in  acute  febrile 
diseases,  in  pneumonia  always,  generally  in  pleurisy,  sometimes 
in  malaria,  in  measles,  in  erysipelas,  peritonitis,  miliary  tuber- 
culosis, pyaemia,  and  in  scarlet  fever,  and,  rarely,  in  rachitis,  and 


URINARY  SEDIMENTS. 


123 


in  diabetes  mellitus.  In  phthisis  pulmonalis  a  persistent  reaction 
is  of  grave  significance.  In  miliary  tuberculosis  the  reaction  is  not 
obtained  until  the  third  week,  and,  therefore,  it  may  serve  to  dif- 
ferentiate this  disease  from  typhoid  fever. 


URINARY  SEDIMENTS. 

Urinary  sediments  may  be  divided  into  two  groups,  organized  or 
anatomical,  unorganized  or  chemical.  The  anatomical  sediments 
include  mucus  and  pus  cells,  blood  corpuscles,  epithelium,  casts, 
spermatozoa,  fungi,  etc.  The  chemical  sediments  vary  with  the 
reaction  of  the  urine,  acid  urine  containing  amorphous  and  semi- 
cn^stalline  urates  of  sodium  and  potassium,  crystalline  uric  acid, 
calcium  oxalate,  and,  rarely,  crystalline  calcium  acid  phosphate, 
cystin,  leucin  and  tyrosin;  while  alkaline  urine  may  contain  amor- 
phous phosphate  and  carbonate  of  calcium,  crystalline  ammonium 
urate,  ammonium  magnesium  phosphate,  phosphates  of  calcium 
and  magnesium,  and  calcium  oxalate. 

The  sediment  is  separated  from  the  urine  by  deposition,  or, 
better,  by  use  of  the  centrifuge.  When  the  examination  is  to  be 
delayed  it  is  necessary  to  guard  against  fermentative  changes,  and 
for  this  purpose  camphor,  salicylate  of  sodium,  thymol,  formalde- 
hyde, or  chloral  hydrate  may  be  added. 

CHEMICAL  EXAMINATION  OF  THE  SEDIMENT. 

Warmed  with  water:  Soluble;  Urates  (and  hippurates,  normal 
calcium  urate  only  slightly,  leucin,  tyrosin  and  xanthine  slightly). 
Insoluble:  Phosphates,  oxalates,  uric  acid  (cystin,  cholesterol  and, 
possibly,  leucin,  tyrosin  and  xanthine). 

Add  acetic  acid :  Soluble :  Phosphates  and  carbonates,  the  latter 
with' effervescence.  (Leucin  and  tyrosin,  and  xanthine  slightly). 
Insoluble:  Oxalates,  uric  acid  (hippuric  acid,  cystin,  cholesterol, 
sulphates  and,  possibly,  tyrosin). 

Add  hydrochloric  acid:  Soluble:  Oxalates,  phosphates,  and  car- 
bonates (effervescence).  (Urates  and  hippurates  dissolve  but  de- 
compose with  separation  of  uric  and  hippuric  acids  ;  leucin,  tyro- 
sin, cystin  dissolve  ;  sulphates  partially  dissolve.)  Insoluble:  Uric 
acid  (also  hippuric  acid  and  cholesterol,  the  latter  soluble  in  ether). 

Add  sodium  hydroxide:  Soluble:  Uric  acid  (leucin,  tyrosin,  cystin, 
xanthine  and  bilirubin  crystals).  Insoluble:  Oxalates,  phosphates, 


1 24  URINAR  Y  SEDIMENTS. 

carbonates  (sulphates  and  cholesterol).     (Earthy  phosphates  are 
precipitated  from  solution. ) 

As  regards  the  effects  of  the  above  reagents  on  the  possible  or- 
ganic contents:  heat  may  coagulate  albumin;  acetic  add  may  pre- 
cipitate mucin  and  may  dissolve  casts,  etc.;  hydrochloric  acid  may 
precipitate  albumin  and  may  destroy  casts,  etc. ;  sodium  hydroxide 
may  dissolve  mucus  to  a  clear  solution,  and  may  convert  pus  into  a 
thick,  viscous  mass.  Micro-organisms  are  dissolved  by  sodium 
hydroxide  and  are  also  evidenced  by  a  milkiness  in  the  urine,  not 
removable  by  ordinary  filtration. 

ANATOMICAL  SEDIMENTS. 

Mucus  Cells. — Often  present  in  normal  urine.  Round  or  oval 
globules  with  faintly  marked  margins,  averaging  about  0.01  mm. 
in  diameter,  but  sometimes  swelling  to  twice  that  size,  generally 
with  but  a  single  nucleus.  (See  also,  p.  104. ) 

Pus  Cells. — From  suppuration  in  the  urinary  tract.  Similar  to 
mucus  cells  in  appearance,  but  distinguished  by  being  generally 
multinuclear,  the  indistinct  nuclei  being  rendered  more  prominent 
by  addition  of  acetic  acid.  The  pus  cells  are  distinguished  from 
white  blood  corpuscles  by  their  somewhat  larger  size,  their  granu- 
lar appearance  and  their  more  irregular  outlines.  The  addition 
of  alkalies  converts  pus  into  a  gelatinous  mass.  Urine  carrying 
pus  yields  albumin  by  chemical  tests.  (See  also,  p.  121.) 

Blood  Corpuscles. — Recognized  as  more  or  less  yellow  biconcave 
discs  with  smooth  or  crenated  margins,  generally  without  nuclei. 
In  dilute  urine  the  corpuscle  is  often  swollen,  and  occasionally  is 
biconvex  in  form.  In  concentrated  urine  shrunken  and  crenated 
corpuscles  are  common.  (See  also,  p.  118.) 

Epithelium. — Occurs  in  rounded,  cylindrical,  polygonal,  or 
granular  cells,  often  nucleated.  These  may  originate  in  the 
bladder,  ureters,  pelvis  of  the  kidney,  kidney,  urethra,  or  vagina. 
The  large,  flat  "squamous"  cells  from  the  vagina  and  bladder 
are  common  in  the  urine  of  women.  Renal  epithelial  cells  are 
rounded  or  polygonal,  small,  and  often  with  a  large  nucleus. 
Certain  of  the  smaller  round  cells  may  resemble  pus,  but  their 
single  nucleus  and  greater  size  will  easily  distinguish  them.  Epi- 
thelium is  much  increased  by  catarrh  in  the  urinary  organs. 

Casts. — Moulds  of  the  uriniferous  tubules  of  the  kidney,  pointing 
to  a  diseased  condition  of  that  organ,  inflammation,  congestion, 


URINA  R  Y  SEDIMENTS.  \  25 

etc.  Classed,  according  to  appearance,  as  hyaline  and  waxy  casts, 
epithelial  casts,  blood,  fatty,  and  granular  casts.  They  are,  in 
general,  cylindrical  in  shape,  with  rounded  ends,  often  nearly 
transparent  and  difficult  to  identify.  They  are  best  detected  after 
staining  with  iodine  or  with  magenta,  and  by  use  of  concentrated 
light.  They  are  quickly  destroyed  by  the  fermentation  of  the 
urine.  Casts  are  found  in  acute  and  chronic  nephritis,  in  jaun- 
dice, etc.  Hyaline  casts  may  occur  in  all  forms  of  albuminuria, 
in  fever  urine,  and  in  many  chronic  disorders.  As  the  disease  or 
inflammation  progresses,  granular,  epithelial  and  blood  casts  be- 
come more  numerous.  Fatty  casts  indicate  a  fatty  degeneration. 
Blood  casts  indicate  a  renal  hemorrhage.  The  presence  of  casts 
together  with  pus  and  blood  generally  suggests  the  renal  origin  of 
the  latter. 

Fungi,  Bacteria,  etc. — Absent  from  normal  urine  when  passed, 
but  often  developing  rapidly  on  exposure  to  the  air.  Yeast  fungi 
are  often  abundant  in  diabetic  urine.  The  micrococcus  ureaB,  de- 
rived from  the  atmosphere,  multiplies  rapidly  in  urine,  and  is  the 
chief  factor  in  the  ammoniacal  fermentation. 

Bacteria  may  be  examined  for  as  follows:  A  little  of  the  sediment 
is  spread  on  a  cover-glass,  dried,  and  passed  quickly  through  a 
Bunsen  flame,  to  fix  the  layer.  Stain  for  fifteen  minutes  in  warm 
carbol-fuchsin  (fuchsin,  1  part,  absolute  alcohol,  10  parts,  and  5 
per  cent,  phenol,  100  parts),  and  then  dip  for  several  seconds  in 
5  per  cent,  sulphuric  acid.  Wash  with  water,  and  stain  with 
methylene  blue  (concentrated  alcoholic  solution  of  methylene  blue 
30  parts,  0.01  per  cent,  potassium  hydroxide  100  parts).  Wash 
again  with  water,  dry,  and  mount  in  balsam.  Tubercle  bacilli 
appear  red,  all  others  will  be  stained  blue. 

For  Gonococci  spread  the  sediment  on  a  cover-glass  and  fix  by 
heat  as  described  above.  Then  cover  the  deposit  with  a  few  drops 
of  ordinary  methylene  blue  or  violet  solution.  Wash  in  water, 
place  on  a  slide  and  examine  at  once  in  water  or  in  glycerol,  or, 
dry  and  mount  in  balsam.  The  more  or  less  kidney-shaped  gono- 
cocci  are  found  generally  in  pairs  united  by  their  flattened  sur- 
faces. The  presence  of  the  gonococci  within  the  pus  cells  is  par- 
ticularly significant. 

Spermatozoa  are  often  present,  and  may  occasionally  prove  to 
be  of  medico-legal  interest.  Their  characteristic  form  is  easily 
recognizable  under  a  high  power. 


126  URINARY  SEDIMENTS. 

CHEMICAL  SEDIMENTS. 

Uric  Acid. — Common  in  acute  fevers,  uric  acid  diathesis,  gravel, 
etc.  Found  in  acid  urine  in  red  or  brownish-yellow  crystals. 
The  crystals,  which  are  described  as  whetstone,  envelope,  spear 
and  fan-shaped,  are  often  gathered  together  in  bunches  or  in 
rosettes.  They  are  insoluble  in  acids,  but  are  dissolved  by  alka- 
lies, and,  slowly,  by  heat.  The  murexid  test  (p.  113)  may  be 
applied. 

Urates. — In  acid  urine,  associated  with  uric  acid,  we  find  sodium 
and  potassium  acid  urates.  In  alkaline  urine  we  find  crystalline 
or  amorphous  ammonium  urate.  The  urates  are  generally  amor- 
phous, or  in  a  state  of  semi-crystallization  in  the  form  of  balls 
studded  with  spicules.  Crystalline  forms  are  somewhat  more 
common  in  alkaline  than  in  acid  urine.  The  murexid  test 
(p.  113)  may  be  applied. 

Oxalates. — Calcium  oxalate  occurs  in  the  urine  in  small  octa- 
hedra  or  in  envelope  and  dumb-bell  forms.  Its  presence  is  not 
especially  significant,  though  it  may  point  to  mal-assimilation, 
and  is  often  associated  with  an  increase  in  uric  acid. 

Phosphates. — Crystalline  di-calcic  phosphate  may  occur  (rare)  in 
acid  urine.  In  alkaline  urine  we  may  have  amorphous  phosphates 
of  calcium  and  magnesium,  crystalline  tri-magnesic  phosphate 
(rare),  crystalline  di-calcic  phosphate  in  rosettes,  spherules,  or 
dumb-bells,  ammonium  magnesium  phosphate,  "triple  phos- 
phate," in  large  beveled-edged  prisms,  or,  occasionally  in  stellate 
feathery  forms.  When  present  in  freshly  voided  urine,  the  triple 
phosphate  indicates  decomposition  of  the  urine  in  the  bladder. 
The  presence  of  other  crystalline  phosphates  and  of  amorphous 
phosphates  is  not  particularly  significant. 

Carbonates. — Rare  as  a  sediment.  Amorphous  calcium  carbon- 
ate may  occur  in  alkaline  urines,  occasionally  in  imperfect  dumb- 
bell forms,  but  generally  as  rounded  or  oval  granules  with  dark 
contours. 

Leucin. — A  rare  sediment,  occasionally  appearing  in  white  shiny 
Iamella3,  generally,  however,  in  groups  of  yellowish  striated 
spherules,  somewhat  like  those  of  sodium  urate,  but  distinguished 
from  the  latter  by  not  dissolving  on  application  of  heat.  They 
are  distinguished  from  oil-drops  by  their  insolubility  in  ether. 

Tyrosin. — A  rare  sediment,  occurring  with  leucin  in  acute 
atrophy  of  the  liver,  in  small-pox  and  in  typhus.  It  is  usually 


URINBRY  CALCULI.  127 

found  in  the  form  of  yellowish-green  globules,  but  when  pure 
occurs  in  fine  needle-like  crystals  radiating  from  a  center. 

Cystin. — A  rare  sediment,  found  in  colorless  six-sided  transpar- 
ent plates,  often  in  overlapping  masses.  The  crystals  are  soluble 
in  hydrochloric  acid  and  in  ammonia,  but  are  insoluble  in  water. 
A  trace  of  sodium  nitro-prusside  added  to  an  alkaline  solution  of 
cystin  develops  a  violet  color.  Boiled  with  a  drop  of  lead  acetate 
cystin  causes  the  separation  of  black  lead  sulphide.  Cystin  is  of 
interest  chiefly  because  of  its  tendency  to  formation  of  calculi. 

Other  rare  sediments  are,  calcium  sulphate,  hippuric  acid  and 
hippurates,  cholesterol,  xanthine,  fat  globules,  and  bilirubin  crys- 
tals. For  the  behavior  of  these  and  the  other  sediments  with 
chemical  reagents,  see  page  123. 

URINARY  CALCULI. 

Calculi  may  consist  of  uric  acid  and  urates,  of  calcium  oxalate, 
ammonium  oxalate,  and  more  rarely  of  phosphates,  carbonates, 
cystin,  xanthine,  etc.  As  a  rule,  each  calculus  is  built  up  of  two 
or  more  ol  the  above  substances  arranged  in  concentric  layers 
around  a  central  nucleus.  These  layers  may  often  be  separated, 
and  in  the  analysis  should  be  examined  separately. 

Uric  Acid  and  Urates  form  hard  calculi,  generally  smooth,  often 
reddish  or  yellowish-brown  in  color,  and  of  variable  size.  Pure 
Phosphatic  Calculi  are  of  rare  occurrence,  though  we  frequently  find 
phosphates  deposited  around  a  uric  acid  nucleus.  The  Fusible 
Calculus  consists  of  a  mixture  of  calcium,  magnesium,  and  ammo- 
nium phosphates.  It  is  readily  fusible  when  heated,  giving  off 
vapor  of  water  and  ammonia.  It  resembles  chalk  in  appearance 
and  consistency.  Calcium  Oxalate  is  frequently  met  with,  forming 
caculi  often  of  considerable  size,  brown  or  olive  in  color,  and  with 
a  rugged  surface  (mulberry  calculi').  When  small  and  hard,  the 
term  hemp-seed  calculus  is  applied.  The  rare  Cystin  Calculi  are 
more  or  less  transparent  and  waxy  in  appearance,  though  crystal- 
line in  structure.  They  are  commonly  tinted  yellow,  changing  to 
green  on  exposure.  Xanthine  Calculi  are  very  rare.  They  are  de- 
scribed as  yellowish-brown  in  color,  often  with  scattered  white 
spots.  Occasionally  altered  blood  clots  will  form  concretionary 
masses  known  as  Fibrinous  Calculi. 

The  following  scheme  will  serve  as  an  aid  in  the  recognition  of 
the  chief  varieties  of  calculi: 


128  URINARY  CALCULI. 

Powder  the  calculus  and  heat  a  small  portion  of  the  powder  on 
platinum  foil  in  the  Bunsen  flame. 

A.  If  it  chars,  burns,  and  leaves  but  little  residue,  it  probably 
consists  of  either  uric  acid,  urates,  cystin,  xanthine,  or  fibrin.     Test  a 
portion  of  the  powder  with   boiling  water;  if  soluble,  we  have 
urates  ;  if  insoluble,  uric  acid.     Confirm  in  either  case  by  the  mur- 
exid  test. 

Treat  another  portion  of  the  powder  with  hydrochloric  acid,  and 
warm;  a  residue  may  be  uric  acid;  cystin  and  xanthine  go  into 
solution.  Cystin  gives  a  brown  color  with  the  murexid  test  and  is 
soluble  in  ammonium  hydroxide.  The  ammonia  solution  on 
evaporation  yields  the  characteristic  hexagonal  crystals.  For 
other  tests  see  p.  127.  Xanthine  gives  a  yellow  color  with  the 
murexid  test,  but  if  potassium  hydroxide  be  used  instead  of  am- 
monia, it  turns  red,  and,  on  heating,  reddish-violet.  Fibrinous 
calculi  will  be  completely  burned  when  heated,  giving  off  the  char- 
acteristic odor  of  burning  feathers. 

B.  Should  the  powder,  when  heated,  char  but  slightly  and  leave 
a  considerable  residue,  or  possibly  undergo  no  change  at  all,  we 
may  have  phosphates,  oxalates  or  carbonates  of  calcium  and  mag- 
nesium. 

A  fresh  portion  of  the  powder  is  treated  with  dilute  hydrochloric 
acid;  if  soluble  with  effervescence,  carbonates  are  present;  if  soluble 
without  effervescence,  we  have  phosphates  or  oxalates.  A  residue 
will  probably  consist  of  uric  acid.  Filter,  render  alkaline  with 
ammonia,  boil,  acidify  with  acetic  acid,  and  again  filter.  A  white 
pulverulent  residue  is  calcium  oxalate,  which,  if  dried  and  heated 
on  platinum,  is  converted  into  calcium  carbonate,  soluble  in  hydro- 
chloric acid  with  effervescence. 

To  the  filtrate  from  the  calcium  oxalate  add  ammonium  hydrox- 
ide; a  white  precipitate  indicates  calcium  or  magnesium  phosphate. 
To  demonstrate  the  presence  of  phosphate,  calcium,  and  magne- 
sium, separately,  to  a  portion  of  the  above  filtrate  from  the  cal- 
cium oxalate  add  neutral  ferric  chloride — a  precipitate  =  phosphate. 
To  the  rest  of  the  filtrate  add  ammonium  oxalate.  Filter  off  the 
precipitated  calcium  oxalate,  and  to  the  filtrate  add  a  little  sodium 
phosphate  and  ammonium  hydroxide.  If  magnesium  be  present 
it  is  slowly  precipitated  in  the  form  of  ammonium  magnesium 
phosphate. 

C.  Should  the  powder  when  heated  melt  and  give  off  water 


THE  SWEAT.  129 

vapor  with  fumes  of  ammonia,  the  calculus  consists  of  a  mixture 
of  calcium,  magnesium,  and  ammonium  phosphates.  (The  Fus- 
ible Calculus. ) 


THE  SWEAT. 


THE  sweat  or  perspiratory  fluid  generally  contains  in  suspension, 
epithelial  cells  and  fat  globules,  but,  when  filtered,  it  is  a  clear 
colorless  liquid  with  salty  taste  and  characteristic  odor.  The  re- 
action is  frequently  acid,  possibly  from  presence  of  fatty  acids  from 
the  sebum,  but  profuse  sweat  is  generally  neutral  or  alkaline.  The 
specific  gravity  is  about  1.005  and  the  total  solids  about  1.5  per 
cent.  In  normal  sweat  we  find  neutral  fats,  volatile  fatty  acids, 
cholesterol,  traces  of  proteid,  creatinin,  urea,  aromatic  oxyacids, 
etherial  sulphates,  sodium  and  potassium  chlorides,  sulphates,  and 
phosphates.  Ammonium  carbonate  is  generally  present  as  a  result 
of  urea  decomposition;  albumin  is  increased  in  the  acid  sweat  of 
acute  rheumatism;  dextrose  appears  in  diabetes;  urates,  and  oxa- 
lates,  in  gout;  urea  is  increased  in  uraemia;  lactic  acid  appears  in 
puerperal  fever;  bile  pigment  in  jaundice.  Drugs  and  ingested 
poisons  frequently  appear  unchanged  in  the  sweat  and  may  there 
be  detected. 


THE  SALIVA. 


THE  saliva  is  the  mixed  secretion  of  the  parotid,  submaxillary, 
'sublingualj  and  buccal  glands.  It  is  colorless,  clear,  or  faintly 
opalescent,  usually  alkaline  in  reaction,  and  froths  easily.  It 
varies  in  specific  gravity  between  1002  and  1008,  and  contains 
from  0.5  to  1.0  per  cent,  of  solid  matter,  the  latter  consisting  of 
albumin,  mucin,  ptyalin,  and  mineral  salts.  In  suspension  the 
saliva  contains  epithelial  cells,  "  salivary  corpuscles, "  and  lumps 
of  mucus.  The  mineral  matter  includes  chlorides,  bicarbonates, 
phosphates,  and  sulphates  of  sodium,  potassium  and  calcium,  with 
traces  of  other  substances.  On  exposure  to  the  air  the  carbonate 
of  calcium  is  precipitated  and  the  saliva  becomes  clouded. 

The  parotid  saliva  is  watery,  free  from  mucin,  and  is  rich  in 
ptyalin.  The  submaxillary  saliva  contains  more  mucin  that  the 
mixed,  otherwise  it  is  similar.  The  sublingual  is  the  richest  in 
solids,  the  most  viscid,  and  the  most  alkaline  of  the  three. 

Ptyalin,  the  important  amylolytic  enzyme  of  the  saliva,  is  similar 
to,  but  not  identical  with,  malt  diastase.  It  converts  cooked  starch 
into  maltose  and  dextrin,  has  no  action  on  uncooked  starch  grains, 
on  cellulose,  or  on  cane  sugar.  It  acts  slowly  on  glycogen.  The 
ferment  acts  best  in  a  neutral  medium,  at  a  temperature  of  from 
35°  to  40°  C. ;  it  is  not  killed  by  dilute  alkalies,  but  the  action  is 
prevented  entirely  by  the  presence  of  more  than  a  trace  of  free 
acid. 

To  demonstrate  the  properties  of  ptyalin,  test  5,  on  page  74  may 
be  repeated,  first  as  described,  then  with  uncooked  starch,  with 
cane  sugar,  with  cooked  starch  after  first  heating  to  destroy  the  fer- 
ment, and,  finally,  with  cooked  starch  in  the  presence  of  free  acid. 

Saliva  or  sputum  may  be  examined  for  bacteria  by  a  method 
similar  to  that  described  on  page  125,  under  urine.  The  carbol- 
fn chain  stain  is  especially  suitable  for  the  determination  of  tubercle 

bacilli. 

(130) 


THE  GASTRIC  FLUID. 


THE  gastric  fluid  is  a  thin,  almost  colorless  liquid,  with  an  acid 
reaction,  and  a  specific  gravity  of  1001  to  1010.  The  following 
analysis  is  given  by  Schmidt: 

Water 994.404 

Organic  Substances,  chiefly  Pepsin            .         .  3.195 

Hydrochloric  Acid 0.200 

Sodium  Chloride 1.465 

Potassium  Chloride 0.550 

Other  Inorganic  Salts       .         .         ,         .         .  0.186 

The  composition  varies,  however,  during  the  digestive  process 
and  in  disease.  The  average  ' '  total  acidity ' '  is  probably  between 
0.10  and  0.36  per  cent.  The  "free  acid"  is  commonly  stated  as 
from  0.20  to  0.30  per  cent.,  but  these  figures  are  undoubtedly 
high.  With  ordinary  food  the  free  acid  will  rarely  exceed  0.10 
per  cent.  The  hydrochloric  acid  formed  in  the  early  stages  of 
digestion  combines  rapidly  with  the  proteids,  and  is  not  likely  to 
be  detected  in  the  fluid  until  one-half  hour  after  the  meal.  Lactic 
acid  is  commonly  present  in  very  small  amount  and,  under  certain 
conditions,  butyric  and  other  organic  acids  may  appear.  In  fevers, 
in  anasmia,  in  catarrh  of  the  stomach,  etc.,  pepsin  and  hydrochloric 
acid  may  both  be  considerably  reduced.  Hydrochloric  acid  may 
be  absent  in  serious  disease  of  the  gastric  mucous  membrane,  in 
atrophy,  gastric  cancer  and  chronic  catarrh.  On  the  other  hand, 
it  is  often  largely  increased  in  gastric  ulcers.  In  nervous  dyspepsia 
the  hydrochloric  acid  is  normal,  increased,  or  decreased.  As  a 
result  of  excessive  fermentative  changes,  lactic  and  butyric  acids 
may  appear  in  large  amount.  In  such  a  case  there  is  always  a 
corresponding  increase  in  gaseous  products,  the  stomach  is  dis- 
tended and  gaseous  eructations  occur.  Lactic  acid  is  increased 
when  secretion  and  peristalsis  are  deficient;  it  is  characteristically 
increased  in  gastric  carcinoma.  Among  the  abnormal  constituents 
of  the  vomit,  we  may  find  excessive  mucus,  albumin,  blood  and 

(131) 


132  THE  GASTRIC  FLUID. 

bile,  while  in  uraemia,  urea  and  ammonium   carbonate  are  also 
often  present. 

The  clinical  examination  of  the  gastric  fluid  (obtained  generally 
by  use  of  the  stomach  tube  and  expression  about  one  hour  after 
the  administration  of  a  test  breakfast  of  a  dry  roll  and  two-thirds 
of  a  pint  of  water)  is  practically  limited  to  the  determination  of 
the  total  acidity,  hydrochloric  acid,  organic  acids,  and  pepsin 
strength.  The  fluid  is  filtered  and  the  clear  filtrate  tested,  first 
qualitatively,  for  the  acids.  When  lactic  acid  is  to  be  tested  for,  an 
excellent  test  breakfast  is  that  of  Boas,  a  flour  soup  consisting  of  a 
tablespoonful  of  oatmeal  in  a  litre  of  water. 

FREE  HYDROCHLORIC  ACID,  QUALITATIVE.  Gunzberg's  Test. — To 
a  few  drops  of  the  filtered  gastric  fluid  add  an  equal  quantity  of 
Gunzberg's  reagent  (see  Appendix)  and  evaporate  to  dryness  at 
a  gentle  heat.  A  bright  red  ring  will  form  at  the  margin.  It  will 
be  found  convenient  to  use  a  flat  porcelain  dish  for  the  test,  rotat- 
ing the  same  over  a  small  flame  and  avoiding  a  high  temperature. 
Organic  acids  do  not  give  the  reaction,  but  the  test  is  said  to  re- 
spond to  one  part  of  hydrochloric  acid  in  10,000  parts  of  water. 

The  materials  for  Gunzberg's  reagent  being  expensive  and  some- 
times difficult  to  obtain,  Boas'  Test  is  often  substituted.  The  pro- 
cedure is  the  same  as  with  Gunzberg's  test,  and  the  results  are 
practically  as  accurate.  For  Boas'  reagent,  see  Appendix. 

Congo-Red  Test. — In  presence  of  considerable  free  hydrochloric 
acid,  a  dark  blue  spot  is  obtained  by  touching  a  piece  of  Congo-red 
paper  with  a  drop  of  the  gastric  fluid.  A  light  blue  or  violet  spot 
may  be  due  to  organic  acids. 

Methyl-Violet  Test. — To  10  c.c.  of  water  add  a  few  drops  of  a 
solution  of  methyl-violet.  Divide  the  test  solution  into  2  parts, 
and  to  one  add  an  equal  volume  of  filtered  gastric  fluid.  Compare 
with  the  remainder  of  the  test  solution.  A  change  in  color,  from 
violet  to  blue,  indicates  hydrochloric  acid,  but  the  delicacy  of  the 
test  is  destroyed  by  pepsin. 

ORGANIC  ACIDS,  QUALITATIVE.  Ujfelmann's  Test  for  Lactic  Acid. 
— To  Uffelmann's  reagent  (see  Appendix)  add  a  little  of  the  filtered 
gastric  fluid.  The  amethyst  blue  of  the  reagent  is  changed  to  a 
canary  yellow  by  lactic  acid  (1-10,000).  Hydrochloric  acid  may 
decolorize  the  reagent,  and  butyric  acid  turns  it  reddish-brown. 

Other  substances  may  interfere  with  the  direct  test,  and  it  is 
therefore  well  to  first  extract  the  gastric  fluid  filtrate  with  ether, 


THE  GA  STEIC  FL  UID.  1 33 

evaporate  off  the  ether,  dissolve  the  residue  in  a  small  amount  of 
water  and  then  add  to  the  reagent. 

TOTAL  ACIDITY,  QUANTITATIVE. — Dilute  10  c.c.  of  the  filtered 
gastric  fluid  with  about  40  c.c.  of  water,  add  a  few  drops  of  alco- 
holic phenolphthalein  solution,  and  titrate  with  deci-normal 
potassium  hydroxide  until  the  liquid  acquires  a  faint  pink  color. 
The  number  of  c.c.  of  the  deci-normal  alkali  used,  multiplied  by 
0.00364,  will  give  the  weight  in  grammes  of  hydrochloric  acid  in 
the  10  c.c.  of  gastric  fluid.  From  this  the  percentage  may  be 
calculated.  For  convenience  the  total  acids  are  reported,  as  indi- 
cated above,  in  terms  of  hydrochloric  acid. 

The  relative  amounts  of  free  acid,  organic  acids,  and  acid  pro- 
teids,  may  be  determined  by  titrating  a  second,  undiluted,  sample 
of  the  gastric  fluid.  The  deci-normal  alkali  is  added  until  a  drop 
of  the  fluid  under  examination  gives  no  reaction  with  Gunzberg's 
reagent.  The  number  of  c.c.  of  alkali  used  serves  for  the  calcula- 
tion of  the  free  mineral  acid.  The  addition  of  the  deci-normal 
solution  is  continued  until  no  reaction  is  obtained  with  Congo-red 
paper,  and  from  the  number  of  c.c.  used  the  organic  acids  are  esti- 
mated, being  calculated  in  terms  of  hydrochloric  acid.  Phenol- 
phthalein may  now  be  added  to  the  fluid,  and  the  titration  continued 
until  the  pink  color  is  developed.  From  this  last  titration  the  acid 
proteids  are  calculated.  The  total  deci-normal  alkali  used  indi- 
cates the  total  acidity. 

For  the  principles  involved  in  the  above  test,  and  for  the  prep- 
aration of  the  deci-normal  alkali  solution,  see  under  Volumetric 
Analysis,  p.  57. 

PEPSIN.  — The  determination  of  the  pepsin  is  of  little  practical 
value;  it  is  rarely  absent,  and  the  digestion  tests  used  are  subject 
to  other  factors  than  the  pepsin  strength.  Coagulated  egg  albumin 
is  cut  in  discs  1  mm.  thick  and  10  mm.  in  diameter.  Two  discs 
are  placed  in  each  of  4  test  tubes,  together  with  10  c.c.  of  the  fil- 
tered gastric  fluid.  To  one  of  the  tubes  add  2  drops  of  concen- 
trated hydrochloric  acid  and  0.3  gramme  of  pepsin.  To  the  second 
tube  add  acid  alone,  and,  to  the  third,  add  pepsin  alone.  A  com- 
parison of  the  rate  of  digestion  in  the  four  tubes  will  indicate 
whether  there  is  a  deficiency  of  pepsin,  of  acid,  or  of  both,  in  the 
gastric  fluid. 

RATE  OF  ABSORPTION  AND  MOTOR  FUNCTION  OF  STOMACH. — To  as- 
certain the  rate  of  absorption  administer  to  the  patient  a  capsule 


1 34  THE  GASTRIC  FL  UID. 

containing  0. 1  gramme  of  potassium  iodide,  and  after  some  min- 
utes test  the  saliva  for  iodine  by  the  following  method:  Dip  strips 
of  filter  paper  into  starch  paste  and  dry.  Mofsten  a  strip  of  this 
paper  with  the  patient's  saliva,  and  then,  with  a  glass  rod,  touch 
it  with  a  drop  of  nitrous  acid.  The  presence  of  iodine  will  be 
shown  by  the  appearance  of  a  blue  spot.  Normally  the  reaction 
will  be  obtained  in  from  10  to  15  minutes  after  the  administration 
of  the  capsule. 

To  test  the  motor  function  of  the  stomach,  administer  to  the 
patient,  by  capsule,  0.5  to  1.0  gramme  of  salol  (phenyl  salicylate). 
Test  the  urine  after  one  hour  and  after  30  hours  by  the  following 
method:  Dip  a  strip  of  filter  paper  into  the  urine  and  then  touch 
the  moist  paper  with  one  drop  of  a  10  per  cent,  neutral  solution  of 
ferric  chloride.  A  trace  of  salicylic  acid  will  develop  a  violet  col- 
ored ring  around  the  spot.  With  normal  peristaltic  movement  the 
excretion  of  salicylic  acid  will  begin  about  one  hour  after  the  ad- 
ministration of  the  salol,  and  will  be  completed  within  30  hours. 

ARTIFICIAL  DIGESTION. — For  experimental  purposes  the  process 
of  digestion  may  be  imitated  as  described  below.  Thoroughly 
masticate,  so  as  to  mix  well  with  saliva,  a  large  piece  of  bread  and 
place  the  resulting  mass  in  a  beaker.  Add  about  200  c.  c.  of  water 
at  a  temperature  of  40°  C.,  and  keep  at  this  temperature,  on  a 
water-bath,  for  20  minutes.  Then  add  about  100  c.c.  of  artificial 
gastric  juice  (see  Appendix)  and  maintain  at  a  temperature  of  40° 
C.  for  one  hour. 

The  acids,  organic  and  mineral,  may  be  tested  for  as  already 
described.  •  To  recognize  the  products  of  digestion,  etc.,  proceed 
as  follows:  Filter  and  divide  the  filtrate  into  a  number  of  parts. 
Show  the  presence  of  unchanged  starch,  by  means  of  iodine  solu- 
tion. Test  for  maltose  by  Trommer's  or  Fehling's  tests  and  note 
the  violet  tint  due  to  the  presence  of  proteids  (the  Biuret  test). 
Test  for  albumins  by  boiling  a  portion  of  the  clear  liquid.  In  all 
probability  there  will  be  no  precipitate.  To  the  same  hot  liquid 
add  dilute  potassium  hydroxide  to  neutralize  the  acid;  a  precipi- 
tate proves  the  presence  of  an  acid-albumin.  To  another  portion 
add  nitric  acid;  a  precipitate  in  the  cold,  soluble  on  heating,  and 
reprecipitated  on  cooling,  indicates  proteoses.  Saturate  a  portion 
of  the  liquid  with  ammonium  sulphate,  filter,  and  test  for  peptones 
with  picric  acid. 

For  the  salivary  digestion  of  carbohydrates,  see  p.  130. 


THE  PANCREATIC  FLUID. 


NORMALLY  the  secretion  of  the  pancreas  is  a  clear  alkaline  liquid 
with  approximately  the  following  percentage  composition  (Zawad- 
sky):  Water,  86.40;  solids,  13.59,  of  which  13.25,  including  9.20 
of  proteid,  is  organic.  In  other  analyses  the  total  solids  have 
varied  between  2  and  15  per  cent. 

The  ferments  of  the  pancreatic  fluid  are  three  in  number, 
trypsin,  a  proteolytic  ferment,  amylopsin,  an  amylolytic  ferment, 
and  steapsin,  a  steatolytic  ferment.  (A  fourth,  a  milk-curdling 
ferment,  is  mentioned.  Trypsin  resembles  the  pepsin  of  the  gastric 
fluid,  converting  albumin  into  peptone;  it  differs  from  pepsin  in 
that  it  acts  best  in  an  alkaline  medium  and  carries  the  digestion 
further,  with  the  production  of  leucin,  tyrosin,  aspartic  acid,  etc. 
Amylopsin  acts  upon  starch,  even  when  raw,  converting  it  into 
maltose  and  dextrin  with  a  trace  of  dextrose.  It  has  no  action  on 
cane  sugar.  Glycogen  is  acted  upon  more  slowrly  than  starch. 
Amylopsin  is  comparable  with,  but  is  a  more  powerful  ferment 
than,  the  ptyalin  of  the  saliva.  Steapsin  splits  fats  into  fatty  acids 
and  glycerol.  The  emulsifying  action  of  the  pancreatic  fluid  as  a 
whole  is,  however,  a  more  important  factor  in  the  preparation  of 
fat  for  absorption. 

An  "  artificial  pancreatic  juice"  may  be  made  by  dissolving  the 
dried  pancreatic  ferments  in  a  one  per  cent,  sodium  carbonate  solu- 
tion. For  the  preparation  of  the  ferments,  a  pancreas  after  stand- 
ing for  a  day  is  minced  and  thoroughly  extracted  (several  days) 
with  glycerol.  Alcohol  is  then  added  to  the  glycerol  extract  and 
the  separated  ferments  are  dried. 

To  demonstrate  the  digestive  process  place  some  of  the  alkaline 
ferment  solution  in  four  test  tubes.  To  one  add  a  small  piece  of 
fibrin.  The  fibrin  is  gradually  eroded,  and  dissolved,  alkali- 
albumin,  proteoses,  and  peptones  are  formed  and  may  be  recog- 
nized by  the  tests  under  proteids,  page  76.  By  long  continued 
digestion  leucin  and  tyrosin  are  also  formed.  To  demonstrate  the 

(135) 


136  THE  PANCREATIC  FLUID. 

leucin,  acidify  the  solution,  boil,  filter,  add  excess  of  absolute 
alcohol  to  the  filtrate,  again  filter,  and  evaporate  the  last  filtrate  to 
a  small  bulk.  Leucin  is  separated  from  the  yellow  fluid  and  may 
be  recognized  under  the  microscope  or  by  other  tests  (see  Index). 
The  tyrosin  may  be  tested  for  as  follows:  Precipitate  the  proteid 
compounds  with  Millon's  reagent,  filter,  and  boil  the  filtrate.  A 
red  color  indicates  tyrosin. 

To  the  second  tube  add  starch  solution,  maltose  and  dextrin  are 
formed.  Compare  with  salivary  digestion,  page  130,  and  apply 
tests.  To  the  third  tube  add  cane  sugar — no  change.  Heat  the 
fluid  in  the  fourth  tube  to  60°  C.  and  then  cool.  Divide  this  solu- 
tion and  test  again  with  fibrin  and  with  starch.  No  reaction  is 
obtained  in  either  case. 

THE  INTESTINAL  FLUID. 

The  secretion  of  the  intestinal  glands  is  an  alkaline  fluid  con- 
taining an  important  enzyme,  Invertin,  an  inverting  ferment 
which  converts  disaccharids,  cane  sugar,  maltose,  lactose,  etc., 
into  the  monosaccharid,  dextrose.  Like  all  alkaline  fluids  the 
secretion  undoubtedly  also  assists  in  the  emulsifying  of  fat. 


THE  BILE. 


THE  bile  is  a  mixture  of  the  secretions  of  the  liver  cells  and  of 
the  mucous  membrane  of  the  biliary  ducts  and  bladder.  It  is  a 
golden-yellow,  greenish,  or  brown,  alkaline  liquid  with  a  specific 
gravity  between  1010  and  1040.  The  lower  specific  gravity,  with 
from  1.5  to  3.0  per  cent,  of  solids,  is  characteristic  of  bile  ob- 
tained from  a  fistula,  Normally  we  have  about  14.0  per  cent,  of 
solids  made  up  as  follows  (Frerichs):  Sodium  glycocholate  and 
taurocholate,  9.14;  cholesterol,  lecithin,  and  fat,  1.18;  mucus  and 
pigment,  2.98;  mineral  salts,  0.78. 

Glycocholic  acid  is  present  in  the  form  of  the  sodium  salt.  On 
decomposition  with  acids,  alkalies,  or  ferments,  it  yields  glycocin 
and  cholalic  acid: 

C26H43N06  +  H20  -CH2NH2COOH  +  C24H4005. 

Taurocholic  acid,  C26H45N07S,  also  present  as  the  sodium  salt, 
on  similar  decomposition  yields  taurin,  C2H7N03S,  and  cholalic 
acid.  Other  acids  are  also  present,  e.  g.,  Fellic  acid,  C23H4004. 
The  principal  bile  pigment  is  Bilirubin,  C16H18N203,  golden- 
yellow,  and  from  this  by  oxidation  we  get  Biliverdin,  green,  con- 
taining one  more  atom  of  oxygen  in  its  molecule. 

TEST  FOR  BILE  ACIDS. 

Pettenkofer'  s  Test.  Add  to  the  bile  concentrated  sulphuric  acid 
and  warm  to  about  60°  C.  Then  add  a  ten  per  cent,  cane  sugar 
solution,  drop  by  drop,  with  constant  stirring.  A  purple-red  color 
turning  to  violet  indicates  the  presence  of  bile  acid. 

The  test  is  due  to  the  decomposition  of  the  bile  acid,  to  the  pro- 
duction of  furfural  by  action  of  the  sulphuric  acid  on  the  sugar, 
and  to  the  combination  of  this  with  the  cholalic  acid.  The  reac- 
tion is  prevented  or  obscured  by  overheating  and  by  excess  of 
sugar.  A  similar  reaction  may  be  given  by  certain  other  sub- 
stances, e.  g.,  oleic  acid,  amyl  alcohol,  and  morphine.  See,  alsov 

page  118. 

(137) 


138  THE  BILE. 

TESTS  FOR  BILE  PIGMENT. 

Gmelin's  Test.  A  drop  of  bile  is  spread  in  a  thin  film  on  a  por- 
celain plate  and  a  drop  of  yellow  nitric  acid  added.  In  the  pres- 
ence of  bile  pigment  the  drop  of  acid  is  surrounded  by  colored 
rings — green  (biliverdin),  blue  (bilicyanin),  and  reddish-yellow 
(choletelin).  Too  much  nitrous  acid  renders  the  succession  of 
colors  indistinct,  and  alcohol  should  be  absent;  proteids  do  not 
interfere. 

Huppert's  Test  may  be  made  as  described  on  page  118  or,  the 
moist  precipitate,  obtained  on  addition  of  lime  water,  may  be 
placed  in  a  test  tube  half  filled  with  acidified  (sulphuric  acid) 
alcohol  and  the  mixture  boiled  for  some  time.  If  pigment  be 
present  an  emerald-green  color  is  developed. 

In  testing  for  bilirubin  in  blood,  precipitate  the  proteid  matter 
"with  alcohol,  filter,  acidify  the  filtrate  with  sulphuric  acid  and 
boil;  the  liquid  becomes  green  in  color. 

See,  also,  page  117. 

BILIARY  CONCRETIONS. 

11  Gall  stones"  may  consist  of  calcium  salts  with  pigment,  the 
so-called  "  pigment  stones,"  or,  more  commonly,  they  are  formed 
of  cholesterol. 

Cholesterol,  C27H45OH,  is  found  in  varying  amount  in  all  the 
tissues  of  the  body,  especially  in  the  brain  and  nerves,  in  semen, 
and  in  the  excretions.  It  may  be  obtained  in  crystalline  plates, 
insoluble  in  water,  dilute  acids  or  alkalies,  soluble  in  boiling  alco- 
hol, in  ether,  chloroform,  oils,  and,  slightly,  in  solutions  of  bile 
salts.  It  may  be  obtained  from  the  concretion  by  crushing,  boil- 
ing with  water,  and  then  with  alcohol.  On  cooling  the  alcoholic 
solution  cholesterol  separates  out.  This  impure  product  is  then 
boiled  with  alcoholic  potassium  hydroxide,  the  alcohol  is  evapor- 
ated, the  residue  extracted  with  ether,  and  the  ether  filtered  and 
evaporated. 

Salkowski's  Test.  Dissolve  the  cholesterol  in  chloroform  and  add 
an  equal  volume  of  concentrated  sulphuric  acid.  The  chloroform 
solution  is  violet-red,  while  the  acid  is  dark  red  with  a  greenish 
fluorescence.  As  a  micro-chemical  test  the  cholesterol  crystal 
touched  with  a  drop  of  sulphuric  acid  shows  colored  rings,  first 
•carmine-red,  then  violet. 


MILK. 


AVERAGE  COMPOSITION  OF  MILK. 


Human  Colos- 

Human Milk 

Cow's  Milk      |      Cow's  Milk 

trum  (Tidy). 

(Leeds). 

(  Konig)  .         (  Hoppe-Sey  ler  )  . 

Water, 

84.077  p.  c. 

86.  732  p.  c. 

87.  17  p.  C. 

85  to  86  p.  c. 

Solids, 

15.923     " 

13.268    " 

12.83     " 

14  to  15    " 

Casein, 

t    3.228     " 

q  no       li 

1.995    " 

3  to    4    " 

Albumin, 

(   0.53 

0.3  to  0.5  " 

Fat, 

5.781     " 

4.131     " 

3.69     " 

-to  4.0  " 

Lactose, 

ftoHc 

6.513     " 
n  S.QK     " 

6.936    " 
n  901     " 

4.88     " 
n  71     « 

4.5  to  5.0  " 

The  salts  consist  of  chlorides  and  phosphates,  of  calcium,  mag- 
nesium, sodium,  and  potassium,  with  a  small  amount  of  iron  and 
a  trace  of  silica.  There  are,  also,  certain  gases  in  solution:  Ac- 
cording to  Pflliger,  100  volumes  of  milk  contain  7.60  of  carbonic 
anhydride,  0.10  of  oxygen  and  0.70  of  nitrogen. 

Frankland  gives  for  woman's  milk  an  average  of  11.4  per  cent, 
solids,  divided  as  follows:  Proteids,  2.7;  Fat,  3.5;  Lactose,  5.0; 
Salts,  0.2.  For  cow's  milk  he  gives  an  average  of  12.5  per  cent, 
solids  divided  into:  Proteids,  4.2;  Fat,  3.8;  Lactose,  3.8;  Salts,  0.7. 
Kotch  gives  as  a  normal  woman's  milk,  12.5  per  cent,  of  Organic 
solids,  including,  Fat,  4.0;  Lactose,  7.0,  and  Casein,  1.5.  The 
variations  in  the  stated  composition  of  woman's  milk  are  due  par- 
tially to  individual  peculiarities  and  partially  to  the  methods  of 
sample  collection.  "Fore  milk"  gives  about  10  per  cent,  solids, 
while  "Stripping"  may  give  as  high  as  15  per  cent.  There  is 
also  a  variation  during  the  day,  afternoon  milk  being  high  in 
solids,  and  the  composition  is  further  affected  by  age,  tempera- 
ment, number  of  pregnancies,  diet,  exercise,  regularity  of  nursing, 
etc. 

Pathological  alterations  may  occur  after  the  administration  of 
certain  drugs,  atropine,  colchicum,  chloral,  opium,  etc.,  and  in 
morbid  conditions.  In  osteomalacia  the  salts  are  increased;  in 

(139) 


140  MILK  ANALYSIS. 

acute  fevers  the  amount  decreases,  the  casein  increases;  in  syphilis 
the  salts  increase,  while  both  casein  and  fat  decrease.  Neurotic 
influences,  catamenia,  and  starvation  lower  the  percentage  of  fat 
and  to  a  less  degree  the  sugar,  while  the  casein  may  be  slightly  in- 
creased. An  over-rich  milk  may  be  due  to  too  liberal  feeding 
without  proper  exercise,  the  solids  in  such  cases  reaching  15-17 
per  cent. 

The  germs  of  infectious  diseases  may  be  recognized  by  physio- 
logical and  microscopical  tests.  Cow's  milk  occasionally  exhibits 
an  abnormal  appearance  due  to  the  presence  of  chromogenic  bacilli, 
not  necessarily,  however,  pathogenic  in  character.  ' '  Red  ' '  and 
"Blue"  milks  are  examples  of  this  phenomenon. 

To  RECOGNIZE  THE  CONSTITUENTS  OF  MILK. 

1. — Dilute  the  milk  in  a  beaker  with  two  or  three  volumes  of 
water,  warm,  and  add  a  few  drops  of  acetic  acid.  Note  the  sepa- 
ration of  the  caseinogen.  This  precipitate  (and  also  the  coagulum 
of  casein,  formed  easily  by  addition  of  rennet)  contains  consider- 
able butter-fat,  which  may  be  extracted  with  ether  after  first  wash- 
ing with  absolute  alcohol.  Filter  off  the  caseinogen  and  reserve 
the  filtrate,  the  Whey,  for  tests  2  and  3.  Test  the  caseinogen  as 
follows:  (a)  Apply  the  xantho-proteic  test.  (6)  Apply  Millon's 
test,  (c)  Warm  with  water  and  add  a  few  drops  of  sodium 
hydroxide;  the  caseinogen  goes  into  solution  and  may  be  repre- 
cipitated  by  addition,  to  neutralization,  of  dilute  acetic  acid. 

2. — Test  the  whey  for  Lactose  as  follows:  (a)  By  Moore's  Test. 
(b)  By  Trommer's  Test. 

3. — Test  the  whey  for  Inorganic  Constituents.  Place  the  whey  in 
an  evaporating  dish,  add  a  few  grains  of  sodium  or  potassium 
nitrate,  and  evaporate  to  dryness  with  occasional  stirring.  When 
the  mixture  is  near  dryness  heat  cautiously  until  it  ignites.  Then 
heat  strongly  until  a  white  ash  remains.  Let  it  cool,  add  a  little 
water  and  a  few  drops  of  dilute  nitric  acid,  warm  gently,  and  filter. 
Divide  the  filtrate  into  2  parts  and  test:  (a)  For  Phosphates,  with 
ammonia  and  magnesia  mixture,  (b)  For  Chlorides,  with  nitric 
acid  and  silver  nitrate. 

4. — To  some  cream  in  a  test-tube,  add  a  little  sodium  hydroxide 
and  a  few  drops  of  alcohol.  Warm  gently  and  note  the  character- 
istic odor  of  butyric  ether,  indicating  the  presence  of  Butter-Fat. 

5. — To  separate  the  Butter- Fat,  add  to  the  milk  one-half  its 
volume  of  sodium  hydroxide,  and  one-half  of  ether.  Shake  well 


MILK  ANAL  YSIS.  141 

and  let  it  stand  in  a  warm  place.  The  fat  dissolves  in  the  ether 
and  floats  on  the  top.  The  ethereal  layer  may  be  removed  and 
the  ether  evaporated,  leaving  the  fat  in  a  pure  state. 

CLINICAL  ANALYSIS  OF  MILK. 

QUANTITY.  The  normal  amount  secreted  by  a  healthy  woman 
may  be  placed  at  from  700  to  1000  c.c.  daily.  A  cow  in  good 
condition  secretes  6000  to  7000  c.c.  daily,  or  about  four  times  its 
body  weight  in  the  year. 

REACTION.  Tested  with  litmu  s  paper,  human  milk  is  normally 
faintly  alkaline.  The  milk  of  the  cow  and  other  herbivora  may  be 
alkaline  or  amphoteric  in  reaction  wh  en  first  passed,  but  becomes 
acid  on  standing.  Milk  of  the  carnivora  is  acid  in  reaction. 

SPECIFIC  GRAVITY.  The  specific  gravity  of  milk  varies  normally 
from  1028  to  1034.  It  is  raised  by  the  removal  of  the  cream  and 
lowered  by  the  addition  of  water.  When  the  milk  has  suffered 
both  of  these  operations,  therefore,  the  specific  gravity  may  be 
normal.  Method. — The  specific  gravity  is  usually  taken  with  a 
hydrometer  after  a  thorough  shaking  of  the  sample.  When  the 
temperature  of  the  milk  departs  considerably  from  the  tempera- 
ture of  registration  of  the  hydrometer  (usually  60°  F. )  a  correc- 
tion must  be  made.  Sufficiently  accurate  results  may  be  obtained 
by  subtracting  one  from  the  hydrometer  reading  for  each  10°  below 
60°  F.,  or  by  adding  one  to  the  reading  for  each  10°  above  60°  F. 

A  hydrometer  with  specially  constructed  scale,  known  as  the 
lactometer,  is  frequently  used  in  the  municipal  control  of  milk. 
Upon  this  instrument  the  0°  mark  corresponds  to  a  specific  gravity 
of  1000,  that  of  pure  water,  while  100°  corresponds  to  a  specific 
gravity  of  1029,  the  minimum  acceptable  specific  gravity  for  pure 
milk.  The  scale  is  commonly  extended  to  130°,  120°  correspond- 
ing to  a  specific  gravity  of  1034,  the  maximum  for  pure  milk. 

FAT.  (Cream.)— (a)  By  the  Creamometer. — A  glass  cylinder 
graduated  into  100  parts  from  above  downward,  is  filled  to  the 
zero  mark  with  the  well  shaken  sample.  After  standing  for  24 
hours  in  a  cool  place,  the  percentage  of  separated  cream  may  be 
read  directly  from  the  graduations.  This  should  be  between  10 
and  20  volumes.  Comparing  with  the  specific  gravity,  less  than 
10  volumes  in  a  milk  of  specific  gravity  above  1033  indicates 
skimming.  Less  than  20  volumes  in  a  milk  of  specific  gravity  be- 
low 1029,  indicates  the  addition  of  water.  There  are,  however, 


142  MILK  ANAL  YSIS. 

several  possible  sources  of  error  in  this  method.  Cream  varies  in 
consistency  and  consequently  in  bulk,  and  moreover,  the  addition 
of  water  causes  a  rapid  separation  of  the  cream  with  an  apparent 
increase  in  quantity. 

(6)  By  Feser's  Lactoscope. — This  method  depends  upon  the  fact 
that  the  relative  opacity  of  milk  varies  with  the  number  of  sus- 
pended fat  globules.  Four  c.  c.  of  milk  are  introduced  into  the 
instrument  and  water  added  until  the  black  lines  upon  the  inner 
cylinder  are  plainly  visible.  The  volume  of  the  mixture  indicates, 
by  graduations  on  the  outer  tube,  the  percentage  of  fat  in  the 
sample.  Whole  milk  should  show  three  per  cent,  or  over,  by  this 
method. 

(c)  Werner-Schmid  Method. — Ten  c.c.  of  milk  are  measured  into 
a  test-tube  of  50  c.c.  capacity  and  10  c.c.  strong  hydrochloric  acid 
added.     The  tube  is  stoppered  and  heated  in  a  water-bath  until 
the  mixture  turns  a  rather  dark   brown,  when  it  is  cooled  and 
shaken  with  30  c.c.  of  ether.     A  wash-bottle-like  arrangement  of 
cork  (not  rubber)  and  tubes  is  now  substituted  for  the  stopper, 
and  the  lower  end  of  the  exit  tube,  which  is  recurved,  is  so  placed 
as  to  rest  just  above  the  line  dividing  acid  and  ether.     The  ether 
is  blown  out  into  a  weighed  flask  and  two  more  extractions  are 
made,  using,  for  each,  10  c.c.  of  ether,  and  adding  the  extracts  to 
that  first  obtained.     Distil  off  the  ether,  dry  the  fat  at  110°  C., 
and  weigh. 

(d)  By  the  Centrifuge. — The  centrifuge,   modified  and  adapted 
for  the  purpose,    affords  a  convenient  and  sufficiently  accurate 
method  for  the  determination  of  fat  in  milk. 

PROTEIDS.  The  milk  is  diluted  and  treated  with  acetic  acid  and 
carbonic  anhydride  gas.  The  precipitated  caseinogen  is  freed  from 
fat,  by  washing  with  ether,  dried,  and  weighed.  The  filtrate  from 
the  caseinogen  is  evaporated  on  the  water  bath  and  the  albumin 
precipitated  with  acetic  acid  tannin  solution.  The  tannin  is  re- 
moved by  washing  with  dilute  alcohol,  and  the  albumin  remaining 
is  dried  and  weighed. 

The  total  nitrogen  in  milk,  from  which  the  proteids  may  be  cal- 
culated, is  usually  determined  by  Kjeldahl's  method,  for  which 
reference  must  be  made  to  special  text-books. 

The  determination  of  the  proteids  in  milk  offers  many  difficul- 
ties, and  is  generally  omitted  in  the  ordinary  clinical  examination, 
as  is,  also,  the  test  for  sugar  which  follows. 


MILK  ANAL  YSIS.  143 

LACTOSE.  The  milk  is  acidified  with  hydrochloric  acid,  boiled 
and  filtered.  The  filtrate  is  boiled  to  convert  the  lactose  into  glu- 
cose, and  the  latter  is  determined  by  means  of  Fehling's  solution 
(see  under  Sugar  in  Urine),  or,  the  lactose  may  be  directly  titrated, 
10  c.c.  of  Fehling's  being  decomposed  by  0.0676  grammes  of  that 
carbohydrate. 

TOTAL  SOLIDS,  (a)  By  Calculation. — An  approximation,  suf- 
ficiently accurate  for  clinical  purposes,  particularly  in  the  exami- 
nation of  mother's  milk,  may  be  made  by  means  of  Hehner  and 
Richmond's  formula. 

T_F+ (0.2186  XG) 

0.859 

T  =  Total  Solids.  F  =  Fat  percentage,  as  determined  by  Feser's 
lactoscope,  or  by  extraction  with  ether.  G  =  Last  two  figures  of 
the  specific  gravity;  e.  g.,  if  the  specific  gravity  is  1030,  then 

If  the  specific  gravity  and  total  solids  be  known,  the  fat  can  be 
calculated  by  the  same  formula  transposed  as  follows: 

F  =  0.859T  —  0.2186  G; 
or,  if  the  milk  is  poor  and  has  been  skimmed, 

F  =  0.859T  —  0.2186  G— 0.05  (^  —  2.5 


(6)  By  Weight. — Two  grammes  of  milk  are  accurately  weighed 
in  a  platinum  dish  with  about  10  grammes  of  dry  sand  or  powdered 
gypsum.  The  milk  is  then  evaporated  and  the  whole  carefully 
dried  at  100°  C..  until  a  constant  weight  is  obtained.  The  loss 
in  weight  gives  the  water  of  the  milk,  and,  by  difference,  the  total 
solids. 

ASH.  By  incinerating  the  solids  obtained  in  the  last  test,  the 
percentage  of  ash  may  be  determined,  or,  better,  make  a  separate 
determination  as  follows:  To  20  grammes  of  milk  in  a  weighed 
dish  add  6  c.c.  of  nitric  acid,  evaporate  to  dryness  and  burn  at  a 
low  red  heat  until  the  ash  is  free  from  carbon. 

DETECTION  OF  ADULTERANTS  IN  MILK. 

Certain  substances,  e.  g.,  sodium  carbonate,  salicylic  acid,  borax, 
boric  acid,  etc.,  are  occasionally  added  to  milk  for  the  purpose  of 
preservation.  The  presence  of  such  substances  will  probably  be 
indicated  by  an  increase  in  the  amount  of  ash,  and  special  tests 
may  then  be  applied.  For  salicylic  acid  and  salicylates,  acidify  with 


144  MILK  ANAL  YSIS. 

hydrochloric  acid,  filter,  and  shake  the  whey  with  ether.  Evapo- 
rate the  ether  and  test  the  residue  (see  p.  35).  To  test  for  borax 
place  one  drop  of  milk  in  a  porcelain  dish  with  2  drops  of  strong 
hydrochloric  acid  and  2  drops  of  a  saturated  tumeric  tincture. 
Dry  on  a  water-bath  and  when  cool,  by  means  of  a  glass  rod,  add 
one  drop  of  ammonia — a  slate-blue  color,  changing  to  green,  is 
developed  if  borax  be  present.  To  separate  borax  or  boric  acid  from 
the  milk  for  testing,  100  c.c.  are  heated  to  boiling  in  a  covered 
beaker  and  8  c.c.  of  nitric  acid  (1-50)  are  added.  The  milk  is 
then  cooled,  filtered,  one-eighth  gramme  of  sodium  carbonate 
added,  evaporated  to  dryness  and  burned  to  a  gray  ash.  The 
soluble  portion  of  this  ash  is  now  tested  (see  p.  32). 

Formaldehyde  (Formalin),  may  be  tested  for  as  follows:  Dilute 
10  c.c.  of  milk  with  water  and  after  the  addition  of  3  drops  of  acetic 
acid,  add  a  little  Mayer's  solution.  Filter,  and  add  1  c.c.  of 
Schiff's  reagent  (see  Appendix  for  solutions).  After  standing  for 
about  10  minutes  add  2  c.c.  hydrochloric  acid.  The  approximate 
amount  of  formalin  present  will  be  indicated  by  the  depth  of  the 
violet  color  produced.  As  a  second  test,  add  to  10  c.c.  of  the 
sample,  2  c.  c.  of  0. 1  per  cent,  phloroglucinol,  and  a  few  drops  of 
sodium  hydroxide.  A  reddish  color  is  obtained  when  the  milk 
contains  four  parts  of  formaldehyde  per  million.  The  reaction  is 
most  pronounced  with  milk  containing  0.5  per  cent.,  and  fails  with 
solutions  containing  more  than  3.0  per  cent. 

Of  adulterants  proper,  water  is  by  far  the  most  common  and  will 
be  detected  by  variation  in  the  specific  gravity,  total  solids,  etc. 
Annatto,  added  to  increase  the  rich  appearance  of  the  milk,  is  not 
of  itself  harmful.  Its  presence  may  be  detected  by  rendering  the 
milk  alkaline  and  soaking  in  it  strips  of  filter  paper.  These  latter 
will  gradually  acquire  a  yellow  tint.  Starch  may  be  tested  for  by 
the  addition  of  iodine  solution,  a  blue  color  being  developed.  Cane 
Sugar  will  reveal  itself  in  the  taste  and  in  the  proportion  of  total 
solids,  as  well  as  in  the  percentage  of  sugar  found.  Boil  10  c.  c.  of 
the  milk  with  0.1  gramme  of  resorcinol  and  1.0  c.c.  of  hydrochloric 
acid  for  five  minutes.  In  presence  of  cane  sugar  a  red  color  is  ob- 
tained. Chalk  will  be  deposited  on  standing,  and  may  be  tested 
for  in  the  ash.  Other  substances,  but  rarely  met  with,  are  gly- 
cerol,  magnesium  carbonate,  tragacanth,  dextrin,  and  arrow-root. 
These  will  increase  the  total  solids,  and  may  be  identified  by  spe- 
cial tests. 


WATER  ANALYSIS. 


A  WATER  may  be  examined  microscopically  for  the  determination 
of  the  living  forms  contained,  for  the  low  orders  of  vegetable  life, 
the  fungi,  for  disease  germs,  etc. ,  or  it  may  be  examined  chemically 
for  dissolved  mineral  salts  and  for  evidence  of  pollution  by  sewage 
or  by  excreta.  The  microscopical  examination,  unfortunately, 
has  proved  of  little  value  owing  to  the  present  impossibility  of 
positively  differentiating  the  harmless  from  the  disease-producing 
germ,  and  to  the  obvious  difficulty  of  properly  representing  within 
the  boundary  of  a  microscopic  field  the  general  contents  of  any 
considerable  body  of  water.  Microscopically  we  seek  evidence  of 
cholera,  of  typhoid;  chemically  we  seek  evidence  of  the  pollution 
by  which  such  germs,  or  others,  might  obtain  entrance  to  the 
source  of  supply.  If  the  water  be  contaminated  it  is  a  menace  to 
health,  whether  or  not  the  germs  of  a  particular  disease  happen  to 
be  present  at  the  moment,  and  in  the  actual  quart,  or  gallon, 
withdrawn  for  examination.  The  chemical  analysis  of  water  is, 
however,  a  matter  for  the  expert,  and  it  is  rare  that  a  simple  clin- 
ical test  will  be  of  value. 

METHODS  OF  ANALYSIS. 

COLOR. — The  color  of  a  water  is  determined,  in  common  prac- 
tice, by  half  filling  a  two-foot  white  glass  cylinder  fitted  with  flat 
plate  ends.  The  cylinder  is  held  horizontally  before  an  illumin- 
ated white  surface,  and  the  water  column  then  viewed  throughout 
its  length. 

ODOR. — The  odor,  if  any,  is  noted  before  and  after  heating,  the 
water  being  placed  in  a  stoppered  flask. 

REACTION. — The  reaction,  which  is  normally  faintly  acid,  is 
tested  with  lacmoid  (blue  with  alkalies,  red  with  mineral  acids, 
but  unaffected  by  carbonic  acid)  and  with  phenolphthalein  (deep 
red  with  alkalies,  colorless  with  acids,  including  carbonic  acid). 

TOTAL  SOLIDS. — 100  c.c.  of  the  water  are  evaporated  in  a  care- 

(145) 


146  WATER  ANALYSIS. 

fully  weighed  platinum  dish.  After  drying,  the  weight  of  the  dish 
plus  residue  is  determined,  and  the  weight  of  the  residue  then  ob- 
tained by  difference.  By  now  igniting  the  residue  at  a  low  red 
heat,  organic  matter  and  some  volatile  mineral  compounds  are  re- 
moved; cooling  and  weighing,  we  determine,  by  calculation,  the 
organic  and  volatile  solids,  the  mineral  and  non-volatile  solids. 

CHLORINE. — A  standard  solution  of  silver  nitrate  is  prepared,  of 
such  strength  (4.793  grammes  per  litre)  that  each  c.c.  is  equiva- 
lent to  0.001  gramme  of  chlorine,  or,  the  deci-normal  silver  nitrate 
solution  described  on  page  64  may  be  used.  To  100  c.c.  of  the 
water  (if  chlorine  be  very  small  in  amount  evaporate  250  c.c.  of 
water  to  100  c.c.)  add  a  few  drops  of  potassium  chromate  solution, 
and  then,  from  a  burette,  add  the  standard  silver  solution  until  a 
faint,  but  permanent,  reddish  tint  is  developed.  The  number  of 
c.c.  of  silver  nitrate  added,  multiplied  by  the  equivalent  of  each 
c.c.,  will  give  the  amount  of  chlorine  in  the  sample. 

PHOSPHATES. — 500  c.c.  of  the  water  are  slightly  acidified  with 
nitric  acid  and  evaporated  to  50  c.c.  Add  a  few  drops  of  dilute 
ferric  chloride,  and  then  ammonium  hydroxide  in  slight  excess, 
filter,  and  dissolve  the  precipitate  in  a  little  hot  dilute  nitric  acid. 
Evaporate  the  solution  to  5  c.c.,  add  2  c.c.  of  a  solution  of  am- 
monium molybdate,  and  warm.  Phosphates  are  thrown  down  as 
a  yellow  precipitate,  the  amount  of  precipitate  indicating  the 
amount  of  phosphate  present. 

NITROGEN  OF  AMMONIUM  AND  OF  ALBUMINOID  COMPOUNDS.— 
Solutions  required.  Sodium  Carbonate: — 50  grammes  of  the  pure 
salt,  strongly  heated,  dissolved  in  250  c.c.  of  distilled  water  and 
boiled  down  to  200  c.c.  Standard  Ammonium  Chloride: — 0.382 
gramme  pure,  dry,  ammonium  chloride,  dissolved  in  100  c.c. 
ammonia-free  water.  For  use,  1  c.c.  of  this  solution  is  diluted  to 
100  c.c.,  each  c.c.  of  the  diluted  solution  being  then  equivalent  to 
0.00001  gramme  of  nitrogen.  Ammonia-free  Water: — Acidulate 
distilled  water  with  sulphuric  acid  and  redistil  from  a  glass  retort. 
Nessler's  Reagent: — 35  grammes  of  potassium  iodide  are  dissolved 
in  100  c.c.  of  water;  17  grammes  of  mercuric  chloride  are  dissolved 
in  300  c.c.  of  water  and  added  to  the  potassium  iodide  solution 
until  a  slight  permanent  precipitate  is  obtained.  Dilute  the  mix- 
ture to  1000  c.c.  with  20  p.  c.  sodium  hydroxide,  and  again  add 
the  mercuric  chloride  until  a  slight  permanent  precipitate  is  ob- 
ained.  Alkaline  Potassium  Permanganate : — 200  grammes  of  potas- 


WATER  ANALYSIS.  147 

slum  hydroxide  and  8  grammes  of  potassium  permanganate  are 
dissolved  in  1000  c.c.  of  distilled  water,  boiled  down  to  750  c.c., 
and  again  made  up  to  1000  c.c.  with  ammonia-free  water. 

Nitrogen  of  Ammonium  Compounds. — Place  in  glass  retort,  properly 
connected  with  a  condenser  and  receiver,  200  c.c.  of  distilled  water 
and  10  c.c.  of  the  sodium  carbonate  solution.  Distil  until  on 
testing  the  distillate  with  Nessler's  reagent  no  reaction  is  obtained. 
Introduce  now,  500  c.c.  of  the  water  under  examination,  and  con- 
tinue the  distillation  at  such  a  rate  that  50  c.c.  of  distillate  will  be 
obtained  in  each  10  minutes.  To  each  50  c.c.,  collected  sepa- 
rately, add  2  c.c.  of  Nessler's  reagent,  and  compare  the  color  ob- 
tained with  a  standard  made  up  of  a  measured  amount  of  the 
ammonium  chloride  diluted  to  50  c.c.  with  ammonia-free  water, 
and  having  2  c.c.  of  Nessler's  reagent  added.  According  as  the 
color  produced  in  the  distillate  is  darker  or  lighter  than  that  of  the 
standard,  prepare  new  standards  containing  more  or  less  of  the 
ammonium  chloride  until,  finally,  the  color  of  standard  and  dis- 
tillate is  the  same.  The  amount  of  nitrogen  in  the  50  c.c.  of  dis- 
tillate will  then  be  equal  to  the  known  amount  of  nitrogen  in  the 
ammonium  chloride  of  the  standard  used.  Continue  the  distilla,- 
tion  and  the  "  Nesslerizing "  until  no  further  color  is  obtained. 
The  sum  of  the  nitrogen  in  the  distillates  will  give  the  "nitrogen 
of  ammonium  compounds  "  in  the  500  c.c.  sample  under  analysis. 

Nitrogen  of  "Albuminoid"  Compounds. — Rinse  out  the  retort  and 
introduce  200  c.c.  of  distilled  water  and  50  c.c.  of  the  alkaline 
potassium  permanganate.  Distil  until  the  distillate  gives  no  re- 
action with  Nessler's  reagent.  Introduce  500  c.c.  of  the  water 
under  examination,  distil,  and  "  Nesslerize,"  as  described  in  the 
last  paragraph.  Subtracting  the  nitrogen  of  ammonium  com- 
pounds, already  determined,  from  the  nitrogen  of  this  second 
operation,  we  obtain  the  "nitrogen  of  albuminoid  compounds." 

NITROGEN  AS  NITRATES. — Solutions  required.  Phenol-sidphonic 
acid: — 37  c.c.  of  strong  sulphuric  acid  added  to  3  c.c.  of  water, 
with  6  grammes  of  pure  phenol.  Standard  Potassium  Nitrate: — 
0.722  grammes  of  pure,  fused,  potassium  nitrate  in  1000  c.c.  of 
water.  Each  c.c.  of  this  solution  contains  0.0001  gramme  of 
nitrogen. 

Process. — Evaporate  a  measured  volume  of  water  to  dryness  in  a 
platinum  dish,  add  1  c.c.  of  phenol-sulphonic  acid,  and,  after 
thoroughly  mixing  with  the  residue,  add  1  c.c.  of  water  and  3 


148  WATER  ANALYSIS. 

drops  of  strong  sulphuric  acid.  Warm  on  the  water  bath,  add  25 
c.c.  of  water,  and  an  excess  of  ammonium  hydroxide,  then  add 
water  to  100  c.c.  Compare  the  color  of  the  solution  (a  yellow) 
with  that  obtained  by  similarly  treating  1  c.c.  of  the  standard 
potassium  nitrate.  •  The  darker  solution  is  diluted  until  the  colors 
are  equal.  The  amount  of  dilution  being  measured,  and  the 
amount  of  nitrogen  in  the  1  c.c.  of  standard  being  known,  the  ni- 
trogen of  the  sample,  nitrogen  as  nitrates,  may  be  easily  calculated. 

NITKOGEN  AS  NITRITES. — Solutions  required.  Sulphanilic  Acid: — 
0.5  gramme  dissolved  in  150  c.c.  of  acetic  acid,  sp.  gr.  1.04. 
Alpha- amido-naphthalene  acetate: — 0.1  gramme  of  solid  naphthyl- 
amine  is  boiled  with  20  c.c.  of  water,  filtered  through  cotton,  and 
mixed  with  180  c.c.  of  diluted  acetic  acid.  The  water  used  must 
be  free  from  nitrites. 

Process. — To  25  c.c.  of  the  water  add  2  c.c.  of  the  sulphanilic 
acid  and  2  c.c.  of  the  arnido-naphthalene  acetate.  In  presence  of 
nitrites  a  pink  color  is  produced,  the  intensity  of  the  color  and  the 
rapidity  of  its  development  being  proportionate  to  the  amount  of 
nitrite  present. 

HARDNESS  OF  WATER. — Water  may  be  "temporarily  hard" 
from  presence  of  carbonates  of  calcium  or  magnesium,  it  may  be 
" permanently  hard"  from  presence  of  the  sulphates  of  the  same 
elements.  Hehner's  Method;  Solutions  required — Sodium  Carbonate: — 
1.06  grammes  of  recently  ignited  sodium  carbonate  are  dissolved 
in  1000  c.c.  of  water.  Each  c.c.  of  this  solution  is  the  equivalent 
of  0.001  gramme  of  calcium  carbonate.  Standard  Sulphuric  Acid: — 
1  c.c.  of  the  strong  acid  is  dissolved  in  1000  c.c.  of  water  and 
tested  with  the  sodium  carbonate  solution,  using  lacmoid  as  the 
indicator.  The  sulphuric  acid  is  then  diluted  until  1  c.c.  will 
exactly  neutralize  1  c.c.  of  the  sodium  carbonate,  each  c.c.  of  the 
acid  solution  being  thus  made  equivalent  to  0.001  gramme  of  cal- 
cium carbonate. 

Process.  For  the  determination  of  the  temporary  hardness,  100 
c.c.  of  the  water,  tinted  with  lacmoid,  are  heated  just  to  boiling, 
and  the  sulphuric  acid  added  until  the  color  changes.  Each  c.c. 
of  the  acid  used  represents  0.001  gramme  of  calcium  carbonate  in 
the  sample  taken. 

For  the  determination  of  the  permanent  hardness,  to  100  c.  c.  of 
the  water  add  a  measured  excess  of  the  sodium  carbonate  solution, 
and  evaporate  to  dryness  in  a  platinum  dish.  Mix  the  residue 


WATER  ANALYSIS.  149 

with  boiling  distilled  water,  filter  and  titrate  the  still  hot  filtrate 
with  the  acid.  The  difference  between  the  number  of  c.c.  of  acid 
used  and  the  number  of  c.c.  of  sodium  carbonate  added,  gives  the 
permanent  hardness  in  terms  of  calcium  carbonate. 

DETECTION  OF  METALS. — In  general,  a  measured  volume  of  water 
may  be  evaporated  to  a  small  bulk  and  examined  by  the  regular 
scheme  (p.  25),  remembering  the  possible  presence  of  phosphates. 
Arsenic,  antimony,  and  mercury  may  be  tested  for,  also,  by  the 
special  tests,  pages  41-43.  Lead  will  be  precipitated  as  the 
brownish-black  sulphide  on  addition  of  a  few  drops  of  ammonium 
sulphide,  the  precipitate  being  insoluble  in  dilute  hydrochloric 
acid  (distinction  from  iron),  insoluble  in  potassium  cyanide  (dis- 
tinction from  copper).  Iron  may  be  tested  for,  directly,  by  boil- 
ing with  a  drop  of  strong  nitric  acid  and  then  adding  potassium 
sulphocyanate,  a  blood-red  color  or  faint  reddish  tint  indicating 
iron  in  large  or  small  amount. 

CLINICAL  TESTS. — The  Total  Solids,  Volatile  Matter,  etc.,  may  be 
determined  as  described.  Chlorine  may  be  easily  determined  as 
described,  or  it  may  be  tested  for  qualitatively,  by  merely  adding 
a  drop  of  silver  nitrate  solution,  best  after  first  acidulating  with 
nitric  acid.  Phosphates  may  be  tested  for  as  described,  or  by  the 
following — Heisch's  Test:  Fill  a  100  c.c.  flask  with  the  water  and 
add  0.5  gramme  of  pure  crystallized  sugar.  Cork  the  flask  and  let 
it  stand  in  the  sunlight,  at  a  temperature  of  27°  C.  for  several 
hours.  A  turbidity,  due  to  a  growth  of  micro-organisms,  indi- 
cates the  presence  of  phosphates. 

An  excess  of  Ammonium  Compounds  may  be  shown,  without  pre- 
vious distillation,  by  the  direct  addition  of  a  few  drops  of  Nessler's 
reagent — a  brownish  color,  or  if  the  ammonium  compounds  be 
present  in  very  large  amount,  a  brownish  precipitate,  will  be  ob- 
tained. (Experiment  with  pure  water,  with  well  water,  with  water 
to  which  a  drop  of  very  dilute  ammonium  hydroxide  has  been 
added,  etc.)  Nitrites,  Nitrates,  and  the  Metals,  may  all  be  tested  for 
as  described.  The  presence  of  Calcium  may  be  demonstrated  by 
addition  to  the  water  of  ammonium  chloride,  ammonium  hydrox- 
ide, and  ammonium  oxalate.  Sulphates  are  shown  by  adding 
barium  chloride  after  first  acidulating  with  hydrochloric  acid. 

INTERPRETATION  OF  RESULTS. 
The  interpretation  of  the  results  of  analysis  will  be  governed  by 


150  WATER  ANALYSIS. 

the  character  of  the  water,  whether  "  surface,"  "subsoil,"  "deep 
well,"  or  "spring,"  and  also  by  the  local  conditions  as  regards 
soil,  cultivation,  population,  proximity  to  the  sea,  etc. 

The  presence  of  a  marked  Color,  Odor,  or  Taste,  will  at  once  sug- 
gest a  contamination  more  or  less  serious,  but,  on  the  other  hand, 
a  water  may  be  perfectly  normal  in  these  respects  and  still  may  be 
dangerously  polluted.  The  Total  Solids  carried  by  natural  waters 
vary  greatly  in  amount;  600  parts  per  million  is  generally  regarded 
as  the  permissible  maximum.  With  an  increase  in  mineral  mat- 
ter the  water  passes  into  the  category  of  mineral  waters  and  be- 
comes a  medicinal  agent.  Organic  matter  of  animal  origin  should 
be  entirely  absent,  nor  should  vegetable  matter  be  present  in  large 
amount. 

Chlorine,  as  sodium  chloride,  is  a  constituent  .of  many  soils  and 
in  certain  localities,  notably  near  the  sea,  may  be  present  in  con- 
siderable amount.  In  absence  of  such  natural  origin,  however, 
chlorine  is  suggestive  of  animal  pollution,  the  chlorides  being  con- 
stant and  indestructible  elements  of  all  sewage  and  excreta. 
Unless  accounted  for  by  mineral  sources,  chlorine  exceeding  10 
parts  per  million  is  to  be  regarded  with  suspicion. 

Phosphates  should  not  exceed  0.6  part  per  million,  phosphates 
like  chlorides  being  characteristic  of  the  excreta.  If  a  marked 
turbidity,  and  especially  if  the  odor  of  butyric  acid,  develop  with 
the  Heisch  clinical  test,  the  water  is  to  be  regarded  as  contam- 
inated. Negative  results  with  phosphate  tests,  however,  are  not 
conclusive  evidence  of  freedom  from  contamination.  Nitrogen  of 
Ammonium  and  Albuminoid  Compounds.  The  nitrogen  of  ammonium 
compounds  (the  so-called  "free  ammonia")  is  subject  to  consider- 
able variation,  but  when  in  large  amount  suggests  organic  con- 
tamination. The  permissible  limit  is  generally  placed  at  0.2-0.5 
part  per  million,  though,  except  with  certain  deep  waters,  an  un- 
contaminated  water  does  not  often  average  more  than  0.04-0.05 
part  per  million.  The  determination  has  little  value,  however, 
unless  considered  with  the  nitrogen  of  albuminoid  compounds  (the 
so-called  "albuminoid  ammonia").  When  the  nitrogen  of 
albuminoid  compounds  is  less  than  0.02  part  per  million,  the 
water  is  generally  free  from  organic  pollution.  If  the  nitrogen  of 
albuminoid  compounds  be  above  0.05  part  per  million,  and  there 
be  a  considerable  amount  of  the  ammonium  compounds,  the  water 
may  be  contaminated;  but  if  the  ammonium  compounds  be  low, 


WATER  ANALYSIS. 


151 


the  water  will  be  acceptable  until  the  albuminoid  nitrogen  reaches 
0.08  part  per  million,  when  the  chlorine  must  be  taken  into 
account.  The  Nitrites  are  usually  evidence  of  existing  fermentative 
changes  and  should  be  absent.  The  Nitrates  represent  the  final 
stage  in  the  oxidation  of  nitrogenous  organic  compounds,  or,  they 
may  be  derived  from  the  mineral  salts  of  the  soil.  In  general,  5 
or  6  parts  per  million  is  regarded  as  a  permissible  maximum. 
The  Hardness  of  water  is  not  of  sanitary  importance  unless  exces- 
sive. It  is  of  interest  more  especially  as  regards  the  use  of  the 
water  in  steam  boilers,  in  the  laundry,  etc. 

It  is  to  be  understood  that  the  figures  given  above  are  subject  to 
local  modification.  It  is,  in  fact,  impossible  to  present  a  set  of 
rigid  standards  universally  applicable;  the  exact  interpretation  of 
a  water  analysis  can  only  be  obtained  as  a  result  of  experience. 

EXAMPLES  OF  WATER  ANALYSES. 
(In  parts  per  million.) 

N.  of  N.  of 

Total    Chlorine.   Ammonium    Albuminoid      N.  of         N.  of 
Solids.  Compounds.  Compounds.    Nitrites.    Nitrates. 


Eain  water,*  Belle- 
fonte,  Pa 

Schuylkill  River 
Water- 
Muddy  *  .    .    .    . 
Filtered    .... 
Distilled  .... 

Driven  Well,  109  feet. 
Devon,  Pa.  Pure. 

Driven  WTell,  75  feet. 
Philadelphia,  Pa. 
Contaminated  .  .  . 

Contaminated   Well, 
Passaic   Co.,    N.    J.  709.0 

Artesian  Well,*  Phila- 
delphia, Pa.  .  .  .  

Spring  Water,  Pure. 
Haverford,  Pa.  .  .  66.0 


5.0   Absent.        0.28 


0.148        Absent.   Absent. 


180.0        

146.0  5.0 

13.0  Absent. 

91.0  7.0 


330.0 


35.4 
123.0 

89.21 


Absent. 
0.06 
0.086 

0.030 


0.306 
0.068 
0.248 


0.180 
0.090 
0.012 


Trace.        0.25 
Absent.   Present. 
Absent.   Absent. 


0.014        Absent.      1.2 


0.070 
0.030 
0.032 


Present.  20.0 
Present,  12.6 
Trace.  Trace. 


7.0        0.028 


0.024        Absent.      2.8 


NOTE.— Analyses  marked  with  asterisk  (*)  are  from  Leffmann  and  Beam,  other  results  are 
from  complete  analyses  by  the  author. 

The  filtered  river  water  is  not  of  the  same  date  as  that  marked  "  muddy."  The  distilled 
water  was  obtained  by  an  ordinary  continuous  distillation  on  a  large  scale.  Results  in  parts 
per  million  may  be  converted  into  grains  per  U.  S.  gallon  by  multiplying  by  0.0584— or  intc 
grains  per  Imperial  gallon,  multiplying  by  0.07. 


APPENDIX. 


WEIGHTS  AND  MEASURES. 


MEASURES  OF  WEIGHT. 

1  milligramme  =        0.001  gramme  —    0.01543  grains,  Troy. 

1  centigramme  =        0.010       " 

1  decigramme    =        0.100       " 

1  gramme  1.000       "        =  15.43235  grains,  Troy. 

1  decagramme  =      10.000  grammes. 

1  hectogramme  —    100.000       " 

1  kilogramme    =1000.000       "        =    2/6790  pounds,  Troy. 

1  kilogramme  =    2.2046  pounds,  Av. 

1  tonneau  =  1000.000  kilogrammes. 


TROY  WEIGHT. 

Pound. 
1 

Ounces. 
12 

Pennyweights. 
240 

Grains. 
5760 

Grammes. 
=     373.2419 

1 

20 

480 

=       31.1035 

1 

24 

1.5552 

Pound. 

Ounces. 

Drachms. 

Scruples. 

Grains. 

1 

12 

96 

288 

5760    = 

1 

8 

24 

480  = 

1 

3 

60  = 

1 

20  = 

1    = 

Grammes. 

373.2419 

31.1035 

3.8879 

1.2959 

0.0648 


AVOIRDUPOIS  WEIGHT. 

Pound.  Ounces.  Drachms.  Grains.  Grammes. 

1  16  256  7000         =  453.5926 

1  16  437.5      =    28.3495 

1  27.343  =       1.7718 

(155) 


156 


APPENDIX. 


Grammes. 

Grains. 

1 

15.43235 

2          = 

30.86470 

3         = 

46.29705 

4 

61.72940 

5          = 

77.16175 

6          = 

92.59410 

n          

108.02645 

8 

123.45880 

9          = 

138.89115 

GRAMMES  AND  GRAINS. 
Grains. 
1 

2 
3 
4 
5 
6 
7 


9 


Grammes. 
0.06479 
0.12958 
0.19437 
0.25916 
0.32395 
0.38874 
0.45353 
0.51832 
0.58311 


MEASURES  OF  CAPACITY. 

1  millilitre  =  1  cubic  centimetre  —      0.061027  cubic  inch. 


1  litre  =  1000  cubic  centimetres  = 


1  kilolitre  =  1000  litres 


0.033816  U.  S.  fluid  ounce. 

16.2310      U.  S. -minims. 

33.816        U.  S.  fluid  ounces. 
=    35.219        Imperial  " 
=      1.0567      U.  S.  quart. 
=  264.18          U.S.  gallons. 


APOTHECARIES'  OR  WINE  MEASURE  (U.  S.). 


Fluid 

Fluid 

Cubic 

Gallon. 

Pints. 

Ounces. 

Drachms. 

Minims. 

Centimetres. 

1 

8 

128 

1024 

61440 

=   3785.432 

(58418.  14  grains)  1 

16 

128 

7680 

=     473.179 

1 

8 

480 

=       29.574 

1 

60 

=         3.696 

1 

0.0616 

IMPERIAL 

MEASURE. 

Fluid 

Fluid 

Cubic 

Gallon. 

Pints. 

Ounces. 

Drachms. 

Minims. 

Centimetres. 

1 

8 

160 

1280 

76800 

=    4543.487 

(70,000  grains) 

1 

20 

160 

9600 

=      567.936 

1 

8 

480 

=        28.396 

1 

60 

3.649 

1 

0.059 

APPENDIX.  157 

MEASURES  OF  LENGTH. 

1  millimetre  =        0.001  metre  =  0.03937  inch. 

1  centimetre  =        0.010      " 

1  decimetre    =        0.100      " 

1  metre  1.000      "      =  3.28089  feet. 

1  decametre  =.      10.000  metres. 

1  hectometre  =  100. 000      < ' 

1  kilometre    =1000.000      "     =  0.62138  mile. 

1  inch  =  2.53995  centimetres. 
1  foot    =  0.30479  metre. 
1  yard  =  0.91438  metre. 
1  mile  =  1.60931  kilometres. 

MEASURES  OF  TEMPERATURE. 

Water  boils.  Water  freezes. 

Centigrade  100°  0° 

Fahrenheit  212°  32° 

Reaumur  80°  0° 

To  convert  °C  to  °F,  multiply  by  9,  divide  by  5,  and  add  32. 
To  convert  °F  to  °C,  subtract  32,  multiply  by  5,  and  divide 
by  9. 

THE  COMMON  ACID  RADICALS. 

1.  Monobasic. — Acetate,  C2H302;  benzoate,  C7H502;  bromide, 
Br;  chlorate,   C103;    chloride,   Cl;  cyanate,    CNO;    cyanide,    CN; 
fluoride,    F;  hypobromite,    BrO;    hypochlorite,    CIO;    hypophos- 
phite,    H2P02;  iodide,    I;  lactate,    C3H5O3;    metaborate,    B02; 
metaphosphate,    P03;    nitrate,    N03;  nitrite,    N02;    perchlorate, 
C104;  salicylate,  C7H503;  sulphocyanate,  CNS. 

2.  Dibasic. — Carbonate,     C03;    chromate,     Cr04;    dichromate, 
Cr207;  metasilicate,    Si03;    molybdate,    MoO4;    oxalate,    C204; 
phosphite,    HP03;  pyro(or   tetra)borate,    B4O7;  sulphate,    SO4; 
sulphide,    S;    sulphite,    SO3;  silicofluoride,    SiF6;    thiosulphate, 
S2O3  =  u hyposulphite  "  of  pharmacy;  tungstate,  W04. 

3.  Tribasic. — Arsenate,    AsO4;    arsenite,    As08;    borate,    B08; 
citrate,  C6H507;  ferricyanide,  Fe(CN)6;  phosphate,  P04. 


158  APPENDIX. 

4.  Tetrabasic. — Ferrocyanide,  Fe(CN)6;  orthosilicate,  Si04; 
pyrophosphate,  P207. 

CONSTRUCTON  OF  FORMULAE. — The  acid  formulae  may  be  obtained  from  the 
above  by  prefixing  H  atoms,  the  number  so  prefixed  being  determined  by  the 
basicity,  e.  g.  Hypochlorous  acid  =  HC1O.  Thiosulphurlc  acid  =  H2S2O3. 
Orthosilicic  acid  =  H4SiO4. 

By  comparison  with  the  table  of  elements,  p.  8,  formulae  for  common  salts  may 
readily  be  ascertained,  e.  g.  To  determine  the  formulae  for  sodium  salicylate, 
potassium1  sulphite,  and  calcium  phosphate. 

Sodium  is  univalent,  the  salicylate  radical  is  univalent  (monobasic),  hence  one 
sodium  atom  unites  with  one  salicylate  radical,  giving  the  formula  NaC7H5O3. 

Potassium  is  univalent,  the  sulphite  radical  is  bivalent  (dibasic),  hence  two 
potassium  atoms  unite  with  one  sulphite  radical,  giving  the  formula  K2SO3. 

Calcium  is  bivalent,  the  phosphate  radical  is  trivalent  (tribasic),  hence  three 
calcium  atoms  unite  with  two  phosphate  radicals,  giving  the  formula  Ca3(PO4)2. 

SOLUBILITIES  OF  COMMON  SALTS. 

GROUP  I.  Pb,  Hg(ous),  Ag.  Soluble  in  Water. — Nitrates,  and 
nitrites  of  all.  Ag,  Pb;  acetates.  Pb;  chloride  (in  hot  water). 

Insoluble  in  Water,  Soluble  in  Acids. — Carbonates,  oxalates,  oxides, 
phosphates,  sulphides,  tartrates,  of  all.  Ag,  Hg;  sulphates.*  Ag; 
bromide.  Pb;  iodide.*  Hg;  iodide. 

Insoluble  in  Water  and  Acids. — Ag;  chloride,  cyanide,  iodide. 
Pb;  chromate,f  sulphate,  f  Hg;  chloride,  f 

GROUP  II  (a).  As,  Sb,  Sn.  Soluble  in  Water. — As;  Arsenates 
and  arsenites  of  alkalies,  chloride  and  iodide  (decomposed  by  hot 
water).  Sb;  chloride  (decomposed  by  excess  of  water),  tartrate. 
Sn(ous):  chloride,  sulphate.  Sn(ic);  chloride. 

Insoluble  in  Water,  Soluble  in  Acids. — As;  arsenates  and  arsenites 
of  metals  other  than  alkalies,  oxide,*  sulphide.  Sb;  oxide,  sul- 
phide. Sn;  oxide,  sulphide.  Sn(ic)  oxide,  f 

GROUP  II  (6).  Hg(ic),  Cu,  Bi,  Cd.  Soluble  in  Water.—  Ace- 
tates, chlorides,  nitrates,  sulphates,  of  all.  (Bi;  chloride  and 
nitrate  decomposed  by  excess  of  water.)  Cu(ous),  Cd;  iodides. 

Insoluble  in  Water,  Soluble  in  Acids. — Carbonates,  oxides,  phos- 
phates, sulphides,  of  all.  Bi;  oxychloride,  oxynitrate,  sub-car- 
bonate. 

Insoluble  in:  Water  and  Acids. — Cu;  ferrocyanide.  Hg;  oxysul- 
phate.  f 

*  Sparingly  soluble  in  water.  f  Sparingly  soluble  in  acids. 


APPENDIX.  159 

GROUP  III.  Fe,  Cr,  Al,  Mn,  Zn,  Ni,  Co.  Soluble  in  Water.— 
Acetates,  chlorides,  nitrates,  sulphates,  of  all.  Fe,  Al,  Ni,  Co; 
citrates.  Fe(ic),  Cr,  Al,  Co;  tartrates.  Fe(oue);  iodide.  Fe(iu); 
ferricyanide,  hypophosphite,*  pyrophosphate  (in  "  scale  prepara- 
tions"). Zn;  chloride,  iodide,  valerianate.  Cr;  chromates  and 
dichromates  of  alkalies.  Mn;  manganates  and  permanganates  of 
alkalies. 

Insoluble  in  Water,  Soluble  in  Acids. — Arsenates,  carbonates,  hy- 
droxides, oxides,  phosphates,  sulphides,  of  all.  Fe(ous)  tartrate. 
Zn,  phosphide. 

Insoluble  in  Water  and  Acids. — Fe;  ferrocyanide.  Fe(ous);  ferri- 
cyanide. Cr;  oxide. f  Al;  oxide,  f  silicate,  f 

GROUP  IV.  Ca,  Ba,  Sr,  Mg.  Soluble  in  Water. — Acetates,  bro- 
mides, chlorates,  chlorides,  iodides,  nitrates,  of  all.  Ba,  Sr,  Ca; 
hydroxides,*  oxides,*  sulphides.  Ca;  chromate,*  citrate,*  hypo- 
phosphite,  sulphate.*  Mg;  chrornate,  citrate,  sulphate. 

Insoluble  in  Water,  Soluble  in  Acids. — Ba,  Ca,  Sr;  carbonates, 
oxalates,  phosphates.  Mg;  carbonate.*  Br,  Sr;  chromates,  sul- 
phites. Mg;  hydroxide,*  oxide.*  Ba;  dioxide  (with  decompo- 
sition). 

Insoluble  in  Water  and  Adds. — Ba,  Sr;  sulphates.* 

GROUP  V.  K,  Na,  Li,  NH4.  Soluble  in  Water. — Li;  benzoate, 
bicarbonate,  bromide,  chloride,  oxide,  salicylate,  sulphate.  K, 
Na;  acetates,  arsenates,  arsenites,  bicarbonates,  bisulphites,  borates, 
carbonates,  chlorates,  cyanides,  hydroxides,  hypochlorites,  hypo- 
phosphites,  iodides,  nitrates,  nitrites,  oxides,  phosphates,  pyro- 
phosphates,  silicates,  sulphates,  sulphides,  sulphites,  thiosulphates 
(hyposulphite  of  U.  S.  P.),  NH4;  bromide,  carbonate,  chloride, 
iodide,  nitrate,  sulphate,  sulphide. 

(Note. — All  common  salts  of  alkalies,  except  those  named  be- 
low, are  soluble  in  water. ) 

Insoluble  in  Water,  Soluble  in  Acids. — K,  NH4;  acid  tartrates,* 
platinic  chlorides.*  K;  perchlorate.*  Na;  antlmonate.  Li;  car- 
bonate, phosphate.* 

*  Sparingly  soluble  in  water.  f  Sparingly  soluble  in  acids. 


160  APPENDIX. 

LIST  OF  REAGENTS.* 

Acid,  Acetic,  HC2H3O2.     Sp.  gr.  1.04,  30  p.  c. ;  U.  S.  P.  acid, 
strong,  sp.  gr.   1.048,  36  p.  c.;  U.  S.  P.  dilute,  sp.  gr. 
1.008,  6  p.  c.     Glacial  Acetic  Acid,  99.5  p.  c. 
11     Hydrochloric,  HC1.     U.  S.  P.  strong,  sp.  gr.  1.16,  31.9 

p.  c.;  U.  S.  P.  dil.,  sp.  gr.  1.05,  10  p.  c. 
"     Hydrosulphuric,  H2S.     A  gas,  by  action  of  FeS  on  HC1. 
"     Nitric,  HN03.     Sp.  gr.   1.24,  32  p.  c.;  U.  S.  P.  strong, 
sp.  gr.   1.414,   68  p.   c.;  U.  S.  P.  dil.,  sp.  gr.  1.057, 
10  p.  c.      "  Yellow  Nitric  ' '   acid,   called  also  Nitrous 
Acid,  contains  N02  in  solution. 
"     Nitrohydrochloric,  NOC1  +  C12.     180  c.c.  U.  S.  P.  strong 

HN08  with  820  c.c.  strong  HC1. 

"     Oxalic,  H2C204.    1  part  crystals  in  10  parts  water  (1-10). 
"     Phosphoric,  H8P04.     U.   S.   P.  strong,  sp.  gr.   1.71,  85 

p.  c.;  U.  S.  P.  dil.,  sp.  gr.  1.057,  10  p.  c. 
"     Picric,  C6H2(N03)3OH.     Saturated  aqueous  solution. 
"     Salicylic,  HC7H603.     Solid  or  in  aqueous  solution. 
"     Sulphuric,  H2S04.     U.  S.  P.  strong,  sp.  gr.  1.835,  92.5 

p.  c.;  U.  S.  P.  dil.,  sp.  gr.  1.070,  10  p.  c. 
"     Tannic,  C14H1009.     4  parts  in  100  parts  of  hot  water. 
"     Tartaric,  H2C4H406.      (1-3.) 
11    Trichloracetic,  HC2C1302.     Solid. 

Acidulated  Brine.  500  c.c.  of  saturated  NaCl  solution,  30  c.c. 
HC1. 

Alcohol,  C2H6OH.     Absolute.     Not  less  than  99  p.  c.  by  weight. 
Place  ordinary  alcohol  in  a  flask  with  quick  lime,  and  after  stand- 
ing several  days  distil  off  at  as  low  a  temperature  as  possible. 
Alcohol.      Ordinary.     About  91  p.  c.  by  weight. 
Almen's     Reagent.       (Nylander's.)      BiON03,     2     grammes; 
NaKC4H4O6,  4  grammes;  NaOH,  8  grammes;  water,  100  c.c. 

Ammonio-Cupric  Sulphate.  To  solution  of  copper  sulphate  add 
ammonium  hydroxide  until  the  precipitate  first  formed  just  redis- 
Bolves. 

Ammonio-Silver  Nitrate.  To  solution  of  silver  nitrate  add 
ammonium  hydroxide  until  the  precipitate  first  formed  just  redis- 
solves. 

*  Certain  special  reagents  will  be  found  described  in  the  text  with  the  tests  in 
which  they  are  used. 


APPENDIX.  161 

Ammonium  Carbonate,  (NH4)2C08.      (1-4.) 
Chloride,  NH4C1.     (1-8.) 
Hydroxide,  NH4OH.     Sp.  gr.  0.96,  10  p.  c.  NH3. 

"Stronger  Ammonia,"  sp.  gr.  0.901,  28  p.  c. 
Molybdate,  (NH4)2Mo04.     10  grammes  dissolved 
in  67  c.c.  of  hot  water,  with  addition  of  a  little 
ammonium  hydroxide  if  necessary,  added  grad- 
ually to  a  mixture  of  33  c.c.  nitric  acid  (sp.  gr. 
1.414)  with  34  c.c.  water. 
Oxalate,  (NH4)2C204.      (1-24.) 
Sulphate,    (NH4)2S04.     Saturated  aqueous  solu- 
tion. 
Sulphydrate,     NH4HS.      Ammonium     hydroxide 

saturated  with  hydrosulphuric  acid. 
Sulphide,  (NH4  )  2S.    Add  f  volume  of  ammonium 

hydroxide  to  one  volume  of  sulphydrate. 

Barfoed's  Reagent.     Dissolve  10  grammes  of  pure  copper  ace- 
tate in  150  c.c.  water,  and  add  4.5  c.c.  U.  S.  P.  acetic  acid. 
Barium  Carbonate,  BaC03.     Solid,  or  saturated  solution. 
"        Chloride,  BaCl2.      (1-10.) 

Hydroxide,  Ba(OH)2.     Saturated  aqueous  solution. 
Mixture.     Two  volumes  of  saturated  solution  of  barium 
hydroxide  with  one  volume  of  saturated  solution  of 
barium  chloride. 
Nitrate,  Ba(N03)2.     (1-10.) 
Bismuth  Subnit'rate,  BiON03  (?).     Solid. 
Bleaching  Powder,  CaOCl2. 

Boas'     Reagent.     Pure   resorcin,    5   grammes;    Cane    sugar,    3 
grammes;  dilute  alcohol,  100  c.c. 

Bromine  Water,  Br.     Aqueous  solution  of  bromine. 
Calcium  Chloride,  CaCl  2 .      ( 1-8. ) 

"         Hydroxide,  Ca( OH)  2 .     Saturated  aqueous  solution. 
Carbol-Fuchsin,  see  p.  125. 
Carbon  Dioxide,  C02.     By  action  of  HC1  on  CaC08. 

"        Bisulphide,  CS2.     Pure. 
Chlorine  Water,  Cl.     Aqueous  solution  of  chlorine. 
Chlorinated  Soda,  for  "Urea  Test.     25  c.c.  solution  of  chlorinated 
soda;  5  c.c.  potassium  bromide  (20  p.  c. ). 

Chloroform,   CHC13.     Sp.   gr.  about  1.49  at  15°  C.     Boils  at 
60°  C. 


162  APPENDIX. 

Cochineal.  (Indicator.)  Macerate  1  gramme/  for  several  days 
with  20  e.c.  alcohol  and  60  c.c.  water.  Filter. 

Collodion.  30  grammes  of  pyroxylin  in  ether  750  c.c.  and 
alcohol  250  c.c. 

Congo-red  Paper.  Prepared  by  soaking  unsized  paper  in  1  p.  c. 
aqueous  solution  of  Congo-red. 

Copper  Sulphate,  CuS04.      (1-8. ) 

Cupric  Ammonium  Hydroxide.  Solution  of  Cu(OH)2  in  am- 
monia. 

Esbach's  Reagent.  Picric  Acid,  10  grammes;  Citric  Acid,  20 
grammes;  Water  to  1000  c.c. 

Ether,  (C2H5)20.   Sp.  gr.  about  0.727  at  15°  C.    Boils  at  37°  C. 

Fehling's  Solution.  Prepared  in  2  parts.  I.  34.639  grammes 
of  pure  crystallized  CuS04,  dissolved  in  water  and  diluted  to  500 
c.c.  II.  173  grammes  Rochelle  salts  and  60  grammes  NaOH,  dis- 
solved in  water  and  diluted  to  500  c.c.  For  use  mix  equal  vol- 
umes of  I.  and  II.  Ten  c.c.  of  the  mixed  solution  =  0.05  gramme 
glucose.  For  use,  1  part  of  the  mixed  solution  is  diluted  with 
about  3  parts  water. 

Ferric  Chloride,  Fe2Cl6.  (1-15.)  Neutral  Ferric  Chloride  may 
be  made  by  adding  dilute  ammonium  hydroxide  until  a  faint  pre- 
cipitate is  obtained.  Filter  and  use  filtrate. 

Ferrous  Sulphate,  FeS04.      (1-10.) 

Frohde's  Reagent.  0.1  gramme  of  sodium  molybdate  in  10  c.c. 
of  cone,  sulphuric  acid. 

Gastric  Juice,  Artificial.  Add  0.3  gramme  of  pepsin  to  100  c.c. 
of  0.3  p.  c.  hydrochloric  acid. 

Gold  Chloride,  AuCl  8 .     ( 1-30. ) 

Guaiac  Mixture.  0.5  gramme  gum  guaiac  in  10  c.c.  alcohol 
with  a  few  drops  of  copper  sulphate  ( 1-2000. ) . 

Gunzberg's  Reagent.  Phloroglucin,  2  pts. ;  Vanillin,  1  pt. ; 
Absolute  Alcohol,  30  pts. ,  by  weight. 

Haines'  Solution.  Dissolve  2  grammes  pure  CuS04  (crys.)  in 
15  c.c.  of  water,  add  15  c.c.  of  pure  glycerol  and  then  150  c.c.  of 
5  p.  c.  KOH  solution.  A  clear  dark  blue  liquid  should  result^ 

Indigo-Carmine  Solution.  1  gramme  commercial  indigo-carmine 
in  150  c.c.  of  water. 

Iodine  Test  Solution.  1  gramme  iodine,  3  grammes  potassium 
iodide,  in  50  c.c.  water. 

Lead  Acetate,  Pb(C2H302)2.     (1-10.) 


APPENDIX.  163 

Litmus  Test  Solution.  Exhaust  powdered  litmus  with  boiling 
alcohol.  Digest  residue  in  cold  water,  filter,  and  extract  residue 
with  boiling  water.  Filter  and  preserve  the  filtrate  as  a  test  solu- 
tion. Litmus  paper  is  prepared  by  impregnating  unsized  paper 
with  the  above  solution. 

Magnesium  Chloride,  MgCl2.      (1-10.) 

Mixture,  1  pt.  cryst.  MgCl2;  2.5  pts.  NH4C1;  5  pts. 
NH4OH,    and    10   pts.    water.     Let  stand,   then 
filter. 
Sulphate,  MgS04.     Saturated  aqueous  solution. 

Mayer's  Solution.  13.546  grammes  HgCl2  dissolved  in  600  c.c. 
of  water.  49.8  grammes  KI  dissolved  in  100  c.c.  of  water.  Mix 
and  dilute  to  1000  c.c. 

Mercuric  Chloride,  HgCl  2 .      ( 1-20. ) 

Mercurous  Nitrate,  Hg2(N03)2.  (1-20.)  Acidulate  with 
nitric  acid, 

Methylene  Blue,  see  p.  125. 

Methylene  Blue  and  Eosin,  see  p.  93. 

Methyl  Orange.  (Tropasolin  D.)  1  gramme  in  1000  c.c.  of 
water.  Add  dilute  sulphuric  acid  drop  by  drop,  until  liquid  just 
turns  red.  Filter. 

Millon's  Reagent.  1  pt.  mercury  treated  with  2  pts.  HN03  in 
the  cold.  Then  heat  on  water  bath,  dilute  with  2  pts.  water,  and 
after  several  hours,  decant  the  clear  liquid. 

Nessler's  Reagent.     See  page  146. 

Nylander's  Reagent.     See  Aim  en's  Reagent. 

Pavy's  Solution.  Copper  sulphate,  3.465  grammes;  Rochelle 
salt,  17  grammes;  potassium  hydroxide,  17  grammes.  Dissolve 
in  distilled  water  and  make  solution  up  to  100  c.c.  Add  333  c.c 
ammonium  hydroxide,  sp.  gr.  0.88,  and  396  c.c.  water.  For  the 
test,  use,  undiluted,  50  c.c.  of  the  solution.  This  will  be  reduced 
by  0.025  gramme  of  glucose. 

Phenolphthalein.  (Indicator.)  1  gramme  in  100  c.c.  dil. 
alcohol. 

Platinic  Chloride,  PtCl4.      (1-10. ) 

Potassium  Carbonate,  K2C03.      (1-20.) 
Chlorate,  KC103.     Solid. 
Chromate,  K2Cr04.      (1-10.) 
"         Dichromate,  K2Cr207.      (1-10.) 

Ferricyanide,  K3Fe(CN)6.      (1-12.) 


164  APPENDIX. 

Potassium  Ferrocyanide,  K4Fe(CN)6.      (1-12.) 
Hydroxide,  KOH.      (1-9.) 
Iodide,  KI.     (1-20.) 
Nitrate,  KNO3.     Solid. 
Sulphate,  K2S04.     (1-12.) 
Potassium  Sulphocyanate,  KCNS.      (1-12.) 
Purdy's  Solution.     CuS04,  4.742  grammes;    glycerol,  38  c.c. ; 
KOH,  23.5  grammes.     Ammonium  hydroxide,  sp.  gr.  0.9,  450 
c.c.     Water  to  1000  c.c.     35  c.c.  of  this  solution  are  reduced  by 
0.02  grammes  of  glucose. 

SchhTs  Keagent.     An  aqueous  solution  of  magenta  (rosaniline- 
hydrochloride)  decolorized  by  sulphur  dioxide. 
Silver  Nitrate,  AgNO  8 .     ( 1-30. ) 
Sodium  Acetate,  NaC2H 3 O2.      (1-5.) 

"        Carbonate,  Na2C03.      (1-5)  or  solid. 
"        Chloride,  NaCl.     Solution. 
Hydroxide,  NaOH.     (1-9.) 
Hydroxide,    Alcoholic.     Solution  of   NaOH   in   dilute 

alcohol. 

Hypobromite,    NaBrO,    for   Urea   test.     100   grammes 

NaOH  in  250  c.c.  water,  with  25  c.c.  bromine  added. 

"        Hypochlorite,  NaCIO,  for  Urea  test.     See  Chlorinated 

Soda. 

Nitroprusside,  Na2FeNO(CN)6.     Aqueous  solution. 
Stannous  Chloride,  SnCl  2 .      (1-6.)     Aqueous  solution. 
Strontium  Nitrate,  Sr(N03)2.     Aqueous  solution. 
Sulphuretted  Hydrogen.     See  Hydrosulphuric  Acid. 
Tanret's  Solution.     HgCl2,  1.35  grammes;  KI,  3.32  grammes; 
Acetic  acid,  20  c.c.     Distilled  water  to  100  c.c. 

UfMmann's  Reagent.  To  10  c.c.  of  1  p.  c.  Phenol  add  2  drops 
of  aqueous  Ferric  Chloride  solution.  Solution  should  be  freshly 
prepared. 

Uranium  Nitrate,  Standard  Solution.     See  page  116. 


POISONS,  AND  THE  TREATMENT 
OF  POISONING. 


GENERAL  PRINCIPLES  OF  TREATMENT. 

1.  Remove  the  poison  from  the  stomach.     Wash  out  the  stomach, 
using  a  stomach  tube,  or  give  emetics,  e.  g.,  zinc  sulphate,  mustard, 
ipecacuanha,  or,  hypodermically,  apomorphine.     Follow  with  pur- 
gatives, e.  g. ,  magnesium  sulphate,  castor  oil,  etc. 

2.  Administer  the  chemical  antidote.     In  poisoning  by  acids,  give 
magnesia  in  water  or  milk.     In  poisoning  by  alkalies,  give  dilute 
acetic  acid,  or  vinegar,  dilute  citric  acid,  or  lemon  juice.    In  poison- 
ing by  alkaloids,  give  a  solution  of  tannin,  or  strong  tea.     The 
chemical  antidote  may  advantageously  be  mixed  with  the  water 
used   in  washing   the   stomach.     When   possible   administer   the 
special  chemical  antidote. 

3.  Administer  the  physiological  antidote,     (a)  When  the  pulse  is 
weak,  intermittent,  or  slow,  sustain  the  heart  by  subcutaneous  in- 
jections of  nitroglycerin,  or  atropin,  or  give  an  enema  of  brandy  or  of 
strong  coffee.     Keep  the  patient  in  a  recumbent  position. 

(b)  When  the  respiration  is  difficult,  keep  the  body  warm,  apply 
cold  affusions  to  the  head,   perform  artificial  respiration,  resort  to 
tracheotomy  if  necessary. 

(c)  When  there  is  coma  or  insensibility,  apply  friction,  flagella- 
tion,  mustard  plasters,  or  administer  excitants,  e.  g.,  strychnine. 
Forced  walking  may  be  resorted  to,   but  not  when  the  heart  is 
affected. 

(d)  When  there  are  convulsions,  spasms,  etc.,  administer  ether 
or  chloroform  by  inhalation,  give  potassium  bromide,  or,  subcutan- 
eously,  morphine.     Chloral  is  not  advised.     Valerian  may  be  given 
per  rectum. 

DOSAGE  OF  REMEDIES  USED. 

ACETIC  ACID.     (36  per  cent.  U.  S.  P.)     Dilute  one  part  with  6 
or  7  parts  of  water. 

(165) 


166  APPENDIX. 

AMYL  NITRITE.     For  inhalation.    2-4  minims.     (0.12-0.24  c.c.) 
APOMORPHINE     HYDROCHLORATE.     Hypodermically,    y1^    grain. 

(0.00648  gramme.) 
ATROPINE  SULPHATE.     Hypodermically,    yi-g-    grain.     (0.00054 

gramme. ) 

BRANDY.     Hypodermic  dose,  20-30  minims.     (1.23-1.84  c.c.) 
CHLORAL.     10-20  grains.      (0.65-1.3  grammes.) 
COPPER  SULPHATE.     10-30  grains.      (0.65-2.0  grammes. ) 
ETHER.     For  inhalation. 

IPECACUANHA.  As  an  emetic,  20  grains  in  water.    (1.3  grammes.) 
MAGNESIA.     Give  freely,  suspended  in  water  or  milk. 
MAGNESIUM  SULPHATE.     Dose  about  one  ounce.     (31  grammes.) 
MORPHINE    SULPHATE.     Hypodermic   dose,    J    grain.      (0.0162 

gramme. ) 

NITROGLYCERIN.      Hypodermic    dose,     TJ-Q    grain.       (0.000648 

gramme. ) 

POTASSIUM  BROMIDE.     10-30  grains,      (0.65-2.0  grammes. ) 
STRYCHNINE  SULPHATE.     Hypodermic  dose,  -fa  grain.     (0.00108 

gramme. ) 

TANNIC  ACID  (Tannin).     10-20  grains.      (0.65-1.30  grammes.) 

ZINC  SULPHATE.     10-30  grains.      (0.65-2.0  grammes. ) 

Other,  special,  remedies  are  given  in  the  list  of  poisons  which 

follows. 

POISONS,  WITH  TREATMENT. 

ACIDS.  (Concentrated. )  Violent  pain,  vomiting,  retching,  hema- 
temesis,  prostration,  collapse,  possibly  asphyxia.  Treatment. — 
Magnesia  in  water  or  milk,  flour  in  milk,  demulcent  drinks,  mor- 
phine to  allay  pain.  Hypodermic  stimulants  in  collapse,  food  per 
rectum. 

ACIDS.  (Dilute.)  Similar  to  concentrated  acids,  less  corrosion, 
more  true  inflammation.  Treatment. — Stomach  tube,  emetics, 
magnesia  in  milk,  barley  water,  etc. 

ACONITINE.  Numbness,  tingling,  deafness,  dimness  of  vision, 
paralysis,  heart  and  respiration  depressed.  Treatment. — Stomach 
tube,  emetics,  nitroglycerin  or  strychnine  hypodermically,  brandy 
enema,  inhalation  of  amyl  nitrite,  recumbent  position,  warmth  to 
body. 

ALCOHOL.  (Spirits,  etc. )  Acute  poisoning.  Dyspnoea,  dilated 
pupils,  convulsions,  stupor,  coma.  Treatment. — Stomach  tube, 


APPENDIX.  167 

emetics,  cold  affusion  to  head,  inhalation  of  amyl  nitrite,  strong 
coffee,  fresh  air,  warmth  to  body. 

ALKALIES.  (Caustic,  concentrated.}  Similar  to  concentrated 
acids,  q.  v.  (Test  reaction  of  vomited  matter. )  Treatment. — Gruel, 
barley  water,  emetics,  morphine  to  allay  pain,  hypodermic  stimu- 
lants, food  per  rectum. 

ALKALIES.  (Dilute. )  Similar  to  dilute  acid,  q.  v.  Treatment. 
— Stomach  tube,  emetics,  dilute  acetic  acid,  vinegar,  lemon  juice? 
demulcent  drinks. 

ALUM.  In  large  doses  an  irritant.  Treatment. — Stomach  tube, 
emetics,  magnesia,  weak  solution  of  ammonium  carbonate. 

AMMONIA.  The  fumes  cause  laryngeal  spasms,  coughing,  etc. 
Treatment. — Inhalation  of  acetic  acid  vapors,  or  of  chloroform. 
Otherwise  ammonia  is  similar  to  other  Alkalies,  q.  v. 

AMYL  NITRITE.  Heart  poison.  Treatment, — Fresh  air,  strych- 
nine or  atropine  hypodermically,  picrotoxin,  recumbent  position. 

ANTIMONY.  (Tartar  emetic.)  Nausea,  retching,  vomiting, 
pain,  purging,  general  depression.  Treatment. — Stomach  tube  if 
necessary,  solution  of  tannin  or  strong  tea,  white  of  eggs,  in  collapse 
strychnine  hypodermically,  brandy  enema,  keep  body  warm. 

ANTIMONY  CHLORIDE.     Similar  to  acids,  q.  v. 

ARNICA.  An  irritant.  Treatment. — Emetics,  alcoholic-  stimu- 
lants, etc. 

ARSENIC.  Thirst,  burning  pain,  vomiting,  purging,  cramps, 
skin  cold,  pulse  small.  Treatment. — Stomach  tube,  emetics,  milk 
with  white  of  egg,  magnesium  sulphate,  magnesia.  Keep  body 
warm,  and,  if  necessary,  relieves  pain  with  morphine.  Special 
antidote:  Freshly  precipitated  ferric  hydroxide.  Add  ammonium 
hydroxide  (or  sodium  carbonate)  to  an  aqueous  solution  of  ferric 
chloride,  filter  through  a  handkerchief,  wash  with  water,  and 
administer  in  teaspoonful  doses. 

ATROPINE.  (Belladonna.)  Face  flushed,  pupils  dilated,  eyes 
prominent,  contraction  of  pharynx,  excitement,  delirium.  Treat- 
ment.— Emetics,  pilocarpin  nitrate  (J— J-  grain),  morphine,  coffee 
enema.  Hot  bags  at  feet,  and  if  necessary,  artificial  respiration. 

BARIUM  SALTS.  Irritants,  pain,  vomiting,  etc.  Treatment. — 
Stomach  tube,  emetics,  magnesium  sulphate,  sodium  sulphate, 
mucilaginous  drinks. 

BELLADONNA.     See  Atropine. 

BICHLORIDE  OF  MERCURY.     See  Mercury. 


168  APPENDIX. 

BROMINE.  Spasmodic  action  of  larynx  and  pharynx,  burning 
pain,  tremor,  and  collapse.  Treatment. — As  under  Iodine,  q.  v. 

BRUCINE.     Similar  to  Strychnine,  q.  v. 

CALABAR  BEAN.     See  Physostigmine. 

CAMPHOR.  In  large  doses  a  cerebral  poison.  Treatment. — 
Stomach  tube,  emetics,  brandy  hypodermically  or  as  an  enema. 
Keep  body  warm. 

CANTHARIDIN.  Blisters,  burning  pain,  dull  pain  in  loins,  urine 
bloody,  genito-urinary  inflammation.  Treatment. — Stomach  tube, 
apomorphine,  magnesium  sulphate,  morphine,  stimulants.  When 
powder  has  been  taken  give  gum  arabic  and  water. 

CARBOLIC  ACID.  (Phenol.)  Faintness,  palor  or  lividity,  pupils 
contracted,  feeble  pulse,  stertorous  breathing,  coma,  urine  darkens 
on  exposure,  odor  of  breath.  Treatment. — Stomach  tube  to  be 
used  very  cautiously.  Zinc  sulphate,  sodium  sulphate,  or  magnes- 
ium sulphate,  white  of  eggs,  atropine,  brandy,  inhalation  of  amyl 
nitrite,  dilute  acetic  acid  or  diluted  vinegar,  keep  body  warm. 

CASTOR  SEEDS.  Purging,  thirst,  convulsions.  Treatment. — Tannin 
or  strong  tea,  morphine  for  the  pain,  keep  extremities  warm,  and 
give  stimulants. 

CHLORAL.  Local  irritant,  heart  depressed,  coma.  Treatment. — 
Stomach  tube,  emetics,  atropine,  or  strychnine,  brandy  or  coffee 
enema,  amyl  nitrite,  artificial  respiration  if  necessary,  body  warm. 

CHLOROFORM.  (Inhaled.}  Treatment. — Artificial  respiration, 
oxygen,  cold  affusions,  galvanism,  stimulants,  amyl  nitrite, 
strychnine. 

CHLOROFORM.  (Internal.}  Burning  pain,  possibly  vomiting, 
insensibility,  weak  pulse,  dilated  pupils,  stertorous  breathing. 
Treatment. — Stomach  tube,  emetics,  enema  of  coffee,  amyl  nitrite, 
artificial  respiration. 

CHROMIUM  SALTS.  Vomiting,  diarrhoea,  etc.  Treatment. — Stom- 
ach tube,  emetics,  magnesia,  barley  water,  etc. 

COCAINE.  Faintness,  dizziness,  weak  pulse,  delirium  or  coma, 
sometimes  paralysis.  Treatment. — Stomach  tube,  emetics,  fresh  air. 

COCCULUS  INDICUS.  Nausea,  debility,  possibly  convulsions. 
Treatment. — Stomach  tube,  emetics,  chloral,  potassium  bromide. 

COLCHICUM.  Thirst,  vomiting,  purging,  exhaustion,  cramps. 
Treatment. — Stomach  tube,  tannin  or  tea,  water,  body  warm,  stim- 
ulants. 

COLOCYNTH.     Similar  to  colchicum,  q.  v. 


APPENDIX.  1 69 

CONIUM.  (Hemlock.)  Weakness,  staggering,  paralysis.  Treat- 
ment.— Stomach  tube,  apomorphine,  tannin,  strychnine,  stimulants. 

COPPER  SALTS.  Vomiting,  purging,  pain.  Treatment. — Apo- 
morphine if  necessary,  warm  milk  with  white  of  egg,  magnesia, 
potassium  ferrocyanide. 

CORROSIVE  SUBLIMATE.     See  Mercury. 

CREOSOTE.     See  Carbolic  Acid. 

CROTON  OIL.  Intense  pain,  vomiting,  purging,  collapse.  Treat- 
ment.— Wash  with  stomach  tube,  demulcent  drinks,  morphine, 
brandy,  stimulants,  camphor  spirits  10  drops  on  sugar  every  ten 
minutes,  keep  body  warm. 

CYANIDES.     Similar  to  Prussic  acid,  q.  v. 

DIGITALIN.  In  large  doses,  pain,  vomiting,  "blue  vision," 
headache,  vertigo,  paralysis  of  heart.  Treatment. — Emetics,  tannin, 
morphine,  aconitine  (-g~J-F  grain),  senega  (15  grains),  recumbent 
position. 

ERGOT.  In  large  doses  acts  as  irritant,  and,  indirectly,  on  heart. 
Treatment. — Zinc  sulphate  as  emetic,  tannin,  tea,  nitroglycerin, 
aconitine  (3--^  grain),  friction,  keep  body  warm. 

ETHER.  Internally  acts  as  an  irritant  and  produces  intoxica- 
tion. Inhaled  is  similar  to  chloroform,  though  not  so  depressing. 
Treatment.  — See  Chloroform. 

FORMALDEHYDE.  (Formalin.)  Vomiting,  pain.  Treatment. — 
White  of  egg,  stomach  tube,  emetics. 

FUSEL  OIL.  (Amyl  alcohol.)  Headache,  nausea,  prostration, 
coma.  Treatment. — See  Alcohol. 

GASES.  (Asphyxia.)  Loss  of  muscular  power,  insensibility, 
labored  breathing.  Treatment. — Artificial  respiration,  fresh  air, 
oxygen,  ozone,  friction,  brandy  hypodermically  or  as  an  enema. 

<^ELSEMIUM.  (Gelsemine. )  Pain  in  eyes,  disturbed  vision, 
weakness,  pain  in  chest,  difficult  respiration.  Treatment. — Stomach 
tube,  emetics,  electricity,  atropine,  nitroglycerin,  artificial  respira- 
tion. 

HEMLOCK.  (Conium  maculatum.  SeeConium.)  Circuta  ma- 
culata  (the  Water  Hemlock),  vomiting,  pain,  violent  convulsions.. 
Treatment. — Emetics,  chloral,  chloroform,  etc. 

HYDROCHLORIC  ACID.     See  Acids. 

HYDROCYANIC  ACID.     See  Prussic  Acid. 

HYOSCYAMINE.     Similar  to  Atropine,  q.  v. 

IODINE.     Pain,  vomiting,  purging,  full  rapid  pulse,  eruptions  on 


170  APPENDIX. 

skin.      Treatment. — Emetics,   starch   and  water,   flour  and  water, 
amyl  nitrite,  morphine  for  pain. 

IODIDES.  Often  produce  catarrhal  symptoms,  voice  reduced, 
little  pain.  Otherwise  similar  to  Iodine.  Treatment. — Stomach 
tube,  emetics,  atropine. 

IODOFORM.  Anorexia,  depression  or  excitement,  rapid  pulse, 
high  temperature,  collapse.  Treatment. — Remove  cause,  and  treat 
symptoms. 

JABORANDT.     See  Pilocarpine. 

LAUDANUM.     See  Morphine. 

LEAD  SALTS.  (Acute.)  Nausea,  burning  in  stomach,  colic, 
retching.  Treatment. — Stomach  tube  and  emetics.  Magnesium 
sulphate,  sodium  sulphate,  potassium  iodide. 

(Chronic.)  Anemia,  fetid  breath,  colic,  constipation,  "wrist 
drop,"  palsy.  Treatment. — Remove  cause  and  nourish. 

LOBELIA.  Motor  depressant,  narcotic,  emetic.  Treatment. — 
Stomach  tube,  brandy,  atropine,  strychnine. 

MERCURY.  (Corrosive  Sublimate.)  Painful  constriction  of 
throat,  burning  pain,  purging,  evacuations  show  mucus  and  blood, 
cold  perspiration,  faintness,  convulsions.  Treatment. — Promote 
vomiting,  white  of  egg  in  milk,  followed  by  stomach  tube,  mag- 
nesia, alkaline  carbonates,  morphine  for  pain. 

MORPHINE.  (Opium,  etc.)  Brief  excitement,  then  weight  in 
limbs,  drowsiness,  sleep,  coma,  pupils  contracted,  labored  breath- 
ing, feeble  pulse,  skin  generally  warm,  muscles  flabby  in  bad  cases. 
Treatment. — Stomach  tube,  emetics,  atropine,  potassium  perman- 
ganate (10  grains  in  water),  coffee  as  enema,  keep  body  warm, 
amyl  nitrite  inhalations,  cold  affusions,  faradization. 

MUSHROOMS.  (Poisonous  Fungi. )  Amanita  muscaria  (Fly  fun- 
gus). Heart's  action  retarded,  difficult  breathing,  stupor,  cold 
sweat,  convulsions.  Treatment. — Stomach  tube,  emetics,  castor 
oil,  atropine  (y-^  to  -fa  grain),  stimulants  and  warmth. 

Amanita  phalloides.  (Death  Cup.)  Pain,  nausea,  vomiting, 
purging,  otherwise  similar  to  A.  muscaria.  Treatment. — Rarely 
satisfactory,  stimulants,  etc.,  physiological  salt  solution  subcu- 
taneously  may  help. 

NICOTINE.  (Tobacco.)  Acts  on  heart  and  respiratory  centers. 
Treatment. — Emetics  if  necessary,  tannin,  brandy,  strychnine, 
recumbent  position  and  warmth. 

NITROBENZENE.  Similar  to  Prussic  acid,  but  with  more  nausea. 
Treatment. — Same  as  for  Prussic  acid. 


APPENDIX.  171 

Nux  VOMICA.     See  Strychnine. 

OPIUM.     See  Morphine. 

OXALIC  ACID.  Similar  to  Acids,  q.  v.,  with  addition  of  depres- 
sion of  heart,  and  other  neurotic  symptoms.  Treatment.— As  for 
Acids,  lime  water  is  excellent,  do  not  use  salts  of  alkalies. 

PHENOL.     See  Carbolic  acid. 

PHOSPHORUS.  Disagreeable  taste,  thirst,  nausea,  vomiting, 
purging,  later  a  jaundiced  condition  and  hemorrhages,  sometimes 
neurotic  symptoms,  cramps,  convulsions.  Treatment. — Copper 
sulphate,  magnesia  in  mucilaginous  drinks,  magnesium  sulphate, 
animal  charcoal,  inhalation  of  oxygen  or  ozone.  Old  oil  of  tur- 
pentine. 

PHYSOSTIGMINE.  (Calabar  bean.)  Prostration,  paralysis  of 
lower  limbs,  pupils  contracted,  asphyxia.  Treatment. — Emetics, 
tannin,  atropine,  strychnine,  artificial  respiration. 

PICROTOXIN.  (Cocculus  Indicus. )  Nausea,  debility,  may  be 
convulsions.  Treatment. — Remove  poison,  potassium  bromide, 
chloral. 

PILOCARPLNE.  Profuse  secretions,  temperature  low,  heart  quick- 
ened, paralysis  of  heart.  Treatment. — Emetics,  tannin,  atropine, 
warmth. 

POTASH.      (Caustic.)     See  alkalies. 

POTASSIUM  CHLORATE.  Vomiting,  diarrhoea,  hemoglobinuria. 
Treatment. — Same  as  for  Potassium  nitrate. 

POTASSIUM  CYANIDE.     Similar  to  Prussic  acid,  q.  v. 

POTASSIUM  NITRATE.  (Nitre.)  Pain,  vomiting,  possibly  con- 
vulsions, or  paralysis.  Treatment. — Stomach  tube,  apomorphine,, 
water,  amyl  nitrite. 

PRUSSIC  ACID.      (Hydrocyanic  acid.)     Vertigo,  loss  of  muscular- 
power,   loss  of  consciousness,  eyes  fixed,  pupils  large,  skin  cold, 
convulsive   breathing.      Treatment. — Stomach  tube,   emetics,  atro- 
pine, brandy,  body  warm,  cold  affusions  to  neck,  artificial  respi- 
ration. 

SILVER  NITRATE.  (Lunar  caustic. )  An  irritant.  Treatment.— 
Stomach  tube,  emetics,  sodium  chloride  freely  in  water. 

SODA.      (Caustic.)     See  Alkalies. 

SOLANIN.     Similar  to  Atropine,  q.  v. 

SNAKE  POISONS.  Local  irritants,  with  heart  and  respiratory 
symptoms.  Treatment. — Suck  wound,  ligature,  wash  with  solution 
of  permanganate,  or,  better,  with  a  fresh  solution  of  calcium  hypo- 


172  APPENDIX. 

chlorite,  inject  hypochlorite  around  wound.  The  hypochlorite 
solution  is  made  by  dissolving  one  part  dry  hypochlorite  of  lime 
in  eleven  parts  of  water.  Hypodermic  dose,  1-2  c.c.,  with  a  total 
of  20  c.c. 

STRAMONIUM.     Similar  to  Atropine,  q.  v. 

STRYCHNINE.  Restlessness,  shuddering,  twitching,  then  tetanic 
convulsions  generally  with  opisthotonos,  followed  by  periods  of 
relaxation.  Treatment. — Emetics,  tannin,  inhalation  of  ether, 
potassium  bromide,  nitroglycerin.  Keep  patient  in  darkened 
room  and  avoid  excitement. 

SULPHURIC  ACID.     See  Acids. 

TARTAR  EMETIC.     See  Antimony. 

TOBACCO.     See  Nicotine. 

VARATRINE.  (Veratrum.)  Pain,  retching,  vomiting,  purging, 
vertigo,  weak  heart  and  pulse.  Treatment. — Promote  vomiting 'if 
necessary,  brandy  or  coffee  enema,  keep  body  warm  and  in 
recumbent  position. 

ZINC  SALTS.  Pain,  vomiting,  purging,  etc.  Treatment. — Emetics 
if  necessary,  white  of  egg  in  milk,  tea,  tannin,  magnesium  sul- 
phate, soap,  magnesia  in  water  or  milk. 


INDEX. 


Absorption  from  stomach,  133 
Acetates,  34,  87,  40 
Acetic  acid,  34,  160.  165 

ether,  43 

Acetone  in  urine,  120 
Achroo-dextrin,  75 
Acid-albumin,  76,  79 
Acidimetry,  60 
Acidophiles,  93 
Acid  radicals,  List  of,  157 

reagents,  160 

Acids  of  gastric  fluid,  132, 133 
Poisoning  by,  166 
Tests  for,  30,  38 
Acidulated  brine  solution,  160 

test,  78 

Aconitine,  48,  55,  65, 166 
Adenine,  53 
Adipose  tissue,  84 
Albumin,  Estimation  of,  106 

in  urine,  104 
Albuminoids.  76,  81 
Albuminometer,  106 
Albumins,  76,  78 
Albumoses,  76,  119 
Alcohol,  43,  160,  166 
Alkali-albumin,  76,  79 
Alkalies,  Poisoning  by,  167 
Alkali  group,  14 
Alkaline  earth  metals,  16 
Alkaloids,  34,  46,  53,  65 
in  urine,  122 
Almen-Bottger  test,  109 
Aim  en's  reagent,  160 
Alpha-naphthol  test,  71,  109 
Alum,  Poisoning  by,  167 
Aluminum,  8,  17,  38 
Ammonia,  10,  167 
Ammonia-free  water,  146 
Ammonio-cupric  sulphate,  160 
Ammonio-silver  nitrate,  160 
Ammonium,  15,  37 

carbonate,  15 

compounds  in  water, 
146 

hydroxide,  15 

salts  as  reagents,  161 
Amygdalin,  53 
Amyl  nitrite,  166, 167 
Amyloid  substance,  81 


Amylolytic  ferments,  88 

Amylopsin,  88,  135 

A  my  loses,  69 

Ansemia,  94,  95 

Analysis,  General  plan  of,  36 

Yolurnetric,  57 

Analytical  scheme  for  metals,  25 
Aniline,  55 
Annatto,  144 
Antimony,  8,  21, 37,  42, 167 

chloride,  167 
Apomorphine,  166 
Arachnidin,  86 
Argon,  8 
Arnica,  167 
Arsenates,  21,  37 
Arsenic,  8,  20,  37,  41, 167 

compounds,  21 
Arsenites,  21,  37 
Arsenous  compounds,  20 
Atmosphere,  Composition  of,  10 
Atomic  weights  of  elements,  8 
Atropine,  48,  55,  65, 167 

sulphate,  dosage,  166 


Bacteria  in  urine,  125 
Barfoed's  reagent,  161 

test,  71 
Barium,  8, 16 

salts  as  reagents,  161 

poisoning  by,  167 

Bartley's  method  for  uric  acid,  113 
Baryta  mixture.  161 
Basophiles,  93 
Belladonna,  see  Atropine. 
Benzoates,  37,  40 
Berber ine,  55 
Beryllium,  8 
Bile  acids,  Tests  for,  137 

Composition  of,  137 

in  urine,  117 

pigments,  Tests  for,  138 
Biliary  concretions,  138 
Bilirubin,  137 
Biliverdin,  137 
Bismuth,  8,  22,  37 

subnitrate,  161 
Biuret  reaction,  77 
Bleaching  powder,  161 
Blood,  Color  ratio  of,  97 
173) 


174 


INDEX. 


Blood,  Composition  of,  91 

corpuscles,  93 

Examination  of,  95 

Haemoglobin  in,  96,  97 

in  disease,  94 

in  urine,  118,  124 

plasma,  92 

platelets,  93 

Specific  gravity  of,  95 

Spectra  of,  94 

Tests  for,  97 
Boas'  reagent,  161 

test,  132 

Borates,  Tests  for,  32,  37,  144 
Borax,  13.  32,  144 
Boric  acid,  13,  32 
Boron,  8 

Bottger's  test,  70,  109 
Brandy,  166 
Bromides,  32,  36,  40 
Bromine,  8,  11,37,  168 

water,  161 

Brucine,  49,  55,  65,  168 
Bryonin,  53 
Butyric  acid,  84 

Cadaverine,  53,  87 
Cadmium,  8,  23,  37 
Caesium,  8 
Caffeine,  49,  55 
Calabar  bean,  168 
Calcium,  8,  17 

salts  as  reagents,  161 
Calculi,  Biliary,  138 

Urinary,  127 
Calomel,  43 
Camphor,  55,  168 
Cane  sugar,  69,  71,  144 
Cantharidin,  55,  168 
Capacity,  Measures  of,  156 
Capric  acid,  84 
Caproic  acioV84 
Caprylic  acid,  84 
Carbohydrates,  69 
Carbol  fuchsin  stain,  125 
Carbolic  acid,  46, 168 
Carbon,  8,  12,  38 
Carbonates,  34,  36,  39 

in  urine,  124 
Carbon  dioxide,  13, 161 
disulphide,  161 
Carbonic  acid,  13,  34 

anhydride,  13 

oxide,  12 

Carbon  monoxide,  12 
Carnine,  53 
Casein,  140 

Caseinogen,  76,  81,  140 
Castile  soap,  85 
Castor  oil,  86 

seeds.  Poisoning  by, 


168 


Casts  in  urine,  124 

Cell-albumin,  76 

Cell-globulin,  76 

Celluloid,  73 

Cellulose,  69,  73 

Centinormal  solutions,  59 

Cerium,  8 

Chautard's  test,  120 

Chloral  hydrate.  44,  166,  168 

Chlorates,  31,36,  37 

Chlorides,  30,  36,  40 

in  urine,  113 

Chlorinated  soda,  161 

Chlorine,  8,  11 

water,  161 

Chloroform,  44, 161, 168 

Chlorosis,  95 

Cholesterol,  92,  121,  138 

Choline,  87 

Chondrigen.  76,  81 

Chondrin,  76,  81 

Chromates,  32 

Chromic  acid,  32,  36,  37 

Chromium,  8,  18 

salts,  Poisoning  by,  1691 

Chyluria,  121 

Chymosin,  88 

Cinchonine,  49,  55,  56,  65 

Citrates,  35,  39 

Citric  acid,  35,  36 

Coagulated  proteids,  76,  81 

Coagulating  ferments,  88 

Coagulation  of  blood,  92 

Cobalt,  8,  20 

Cocaine,  50,  65,  168 

Cochineal,  60,  162 

Cocculus  indicus,  168 

Codeine,  50,  55,  65 

Cod-liver  oil,  86 
j  Colchicine,  55,  168 

Colchicum,  55, 168 

Collagen,  70,  81 

Collodion,  73,  162 

Colocynth,  168 

Colocynthin,  55 

Columbium,  8 

Colustrum,  139 

Congo-red  paper,  162 
test,  132 

Coniine,  47.  55,  65 

Conium,  169 

Copper,  8,  22 

salts  as  reagents,  162 
salts,  Poisoning  by,  169 
sulphate,  dosage,  166 

Corrosive  sublimate,  43 

Creamorneter,  141 

Creosote,  169 

Croton  oil.  169 

Crystallin,'  82 

Curarine,  56 


INDEX. 


175 


Cyanides,  33,  36,  37,  40,  169 
Oystin  in  urine,  127,  128 

Decinormal  solutions,  59,  60,  62,  64 
Dextrin,  69,  74 
Dextrose,  69 
Diabetic  urine,  107 
Diacetic  acid  in  urine,  120 
Diastase,  88 
Diazo-reaction,  122 
Dichromates,  Tests  for,  32 
Digestion,  Artificial,  134 
Digitalin,  53,  55,  169 
Disaccharids,  69 
Donnes'  test  for  pus,  121 
Doremus'  method  for  urea,  112 
DragendorfP s  method,  55 
Drugs  in  urine,  122 

Egg  albumin,  76,  79 
Ehrlich's  reaction,  112 
Einhorn's  test  for  dextrose,  110 
Elastin,  76,  81 
Elaterin,  55 
Eleidin,  76,  81 
Elements,  Table  of,  8 
Emplastrum  plumbi,  86 
Emulsin,  88 
Enzymes,  87 
Eosinophiles,  93 
Epithelium  in  urine,  124. 
Erbium,  8 
Ergot,  169 
Erytbroeytes,  93 
Erythrodextrin,  75 
Esbach's  reagent,  162 

test,  106 

Ether,  44,  162, 166,  169 
Ethyl  acetate,  43 
Ethyl  alcohol,  see  Alcohol. 
Ethyl  ether,  see  Ether. 

Fat  in  milk,  140,  141 

in  urine,  121 
Fats,  84 
Fehling's  solution,  162 

test,  70, 108,  109 
Fellic  acid,  137 
Fermentation  test,  70,  109 
Ferments  and  Fermentation,  87 
Ferric  chloride,  37, 162 

compounds,  19 
Ferricyanides,  39 
Ferrocyanides,  37,  39 
Ferrocyanide  test  for  albumin,  106 
Ferrous  compounds,  18 

sulphate,  162 
Feser's  lactoscope,  142 
Fibrin,  76 

Fibrinogen,  76,  79,.91,  92 
Fibrinoplastin,  79 


Fleitmann's  test,  41 
Fluorine,  8 

Formaldehyde,  45,  144,  169 
Formalin,  45,  144 
Formates,  37 

Fresenius-Babo's  method,  54 
Frohde's  reagent,  162 
Fruit  sugar,  69 
Fulminating  gold,  23 
Fungi  in  urine,  125 

Poisonous,  170 
Fusel  oil,  43, 169 

Gadolinium,  8 

Galactose,  69,  71 

Gallates,  40 

Gallium,  8 

Gall  stones,  138 

Gases,  Poisoning  by,  169 

Gastric  Fluid,  Analysis  of,  132,  133 

Composition  of,  131 
Gastric  juice,  Artificial,  162 
Gelatin,  76,  81 
Gelatinoid  substances,  76 
Gelseniic  acid,  51 
Gelsemine,  50, 169 
Germanium,  8 
Globulins,  76,  79,  119 
Glucic  acid,  69 
Glucinum,  8 
Glucose,  69, 109 
Glucosides,  53 
Glycerides,  84 
Glycerin,  45,  85 
Glycerol,  45,  85 
Glyceryl,  84 
Glycocholic  acid,  137 
Glycocin,  137 
Glycogen,  69,  75 
Glycosuria,  107 
Glycuronic  acid  in  urine,  121 
Gmelin's  test,  117,  138 
Gold,  8,  23 

chloride,  162 
Gonococci,  125 
Granulose,  69.  74 
Grape  sugar,  .See  Dextrose. 
Guaiac  mixture,  162 
Guaiacum  test,  97,  119 
Gun  cotton,  73 
Gunzberg's  reagent,  162 
test,  132 

Haematin,  94 
Hsematoidin,  94 
Hsematoporphyrin,  94 
Hsemin,  94 

Ha3tnin  test  for  blood,  97, 119 
Hsemochromogen,  94 
Haemocytes,  93 
Haemocytometer,  95 


176 


INDEX. 


Haemoglobin,  76,  81,  93 
Haemoglobinsemia,  95 
Haemoglobin  uria,  95 
Haeser's  coefficient,  104 
Haines'  solution,  162 

test,  108 
Halogens,  11 

Haloid  salts,  Estimation  of,  63 
Hardness  of  water,  148 
Heat  test  for  albumin,  78, 105 
Heliner's  test,  148 
Helium,  8 
Helleborin,  53,  55 
Heller's  test  for  blood,  119 
Hemlock,  169 
Hippuric  acid  in  urine,  99 
Hopkin's  method  for  uric  acid,  113 
Huppert's  test  for  bile,  118, 138 
Hydrates,  37,  40 
Hydriodic  acid,  11,33 
Hydrobromic  acid,  11,  32 
Hydrochloric  acid,  11,  30, 160 

in  gastric  fluid,  132 
Hydrocyanic  acid,  33,  171 
Hydrofluoric  acid,  11,  36 
Hydrogen,  8,  9 

dioxide,  10 

sulphide,  12 

Hydrosulphuric  acid,  11,  160 
Hydroxides,  37,  40 
Hydrox.\  butyric  acid,  121 
Hyoscyamine,  55, 169 
Hypobromite  of  sodium,  164 

test  for  urea,  111 
Hypochlorites,  31 ,  36 
Hypophosphites.  34 
Hyposulphites,  31,  36,  37 
Hypoxanthine,  53 

Indican,  117 

Indicators,  59 

Indium,  8 

Indigo-carmine  solution,  162 

test,  70,  109 
Indole,  117 

Indoxyl  sulphate  of  potassium,  117 
Intestinal  fluid,  136     . 
Invertin,  88,  136 
Inverting  ferments,  88 
Invert  sugar,  71 
lodates,  37 

Iodides,  33,  36,  40,  170 
Iodine,  8,  11,  37,  169 
Iodine  test  solution,  162 
lodoform,  43,  170 
Ipecacuanha, 166 
Iridium,  8 
Iron,  8,  18,  37,  38 

Jaborandi,  170 


Keratin,  76,  81 
Kjeldahl's  method,  142 

Lactalbumin,  76,  139,  142 
Lactometer,  141 
Lactoscope,  142 
Lactose,  69,  72,  139,  143 
Lanthanum,  8 
Lardacein,  76,  81 
Laudanum,  170 
Laurie  acid,  84 
Lead,  8,  24.  37 

acetate,  162 

plaster,  85 

salts.  Poisoning  by,  170 
Lecanau's  test  for  blood,  119 
Lecithin,  86 
Legal 's  test,  120 
Length,  Measures  of,  157 
Leucin,  126,  135 
Leucocytes,  93 
Leucocythsemia,  95 
Leucocytpsis,  94 
Leucomaines,  53,  87 
Levulose,  69,  71 
Lithium,  8,  15 
Litmus,  59,  163 
Lobelia,  170 

Loebisch's  coefficient,  104 
Loewe's  test,  70 
Lunar  caustic,  171 

Magnesia,  dosage,  166 

Magnesium,  8,  17 

salts  as  reagents,  163 
sulphate,  dosage.  166 

Malic  acid,  36 

Maltose,  69,  72 

Manganates,  33 

Manganese,  8, 19 

Mannitic  acid,  69 

Man  nose.  69 

Marechal'stest,  117 

Marsh's  test,  41,42 

Mayer's  solution,  163 

Meconates,  39,  40 

Meconic  acid,  51 

Melassic  acid,  69 

Melting  points,  84 

Mercuric  compounds,  21,  37,  43,  163 

Mercurous  compounds,  24, 37, 43, 163 

Mercury,  8,  21,37,  43 

poisoning,  170 

Metaboric  acid,  13 

Metalbumin,  81 

Metals,  Analytical  scheme  for,  25, 29 
Cl  .ssitication  of,  14 
Separation     from     organic 
matter,  53 

Metaphosphates,  34 

Methsemoglobin,  94 


INDEX. 


177 


Methylene  blue,  125 
Methylene  blue  and  eosin,  93 
Methyl  orange,  59,  163 
Methyl  violet  test,  132 
Milk,  Analysis  of,  141 

Composition  of,  189 

Detection  of  adulterants  in, 
143 

Recognition  of  constituents, 
140 

Sugar  of,  69,  72,  139, 143 
Millon's  reaction,  77 
reagent,  163 
Molybdates,  37 
Molybdenum,  8,  37 
Monosaccharids,  69 
Moore's  test,  69 
Morphine,  51,  56,  65,  170 

sulphate,  dosage,  166 
Motor  function  of  stomach,  134 
Mucic  acid,  69 
Mucin,  76,81,104 
Mucus  in  urine,  104,  124 
Murexid  test  for  uric  acid,  113 
Muscle  albumin,  76 
Mushrooms,  Poisoning  by,  170 
Mycose,  69 
Myosin,  76,  88 
Myosinogen,  76 
Myristic  acid,  84 
Myrosin,  88 
Mytelotoxine,  53 

Narceine,  55,  56 
Narcotine,  55 
Neodidymium,  8 
Nephrites,  Urine  in,  105 
Nessler's  reagent,  146     . 
Neuridine,  87 
Neurine,  53,  87 
Neutrophiles,  93 
Nickel,  8,  20 
Nicotine,  47,  55,  65,  170 
Niobium,  8 
Nitrates,  31,36,37 
Nitre,  Poisoning  by,  171 
Nitric  acid,  10,  31, 160 

test   for   albumin,  78, 
105 

anhydride,  10 

oxide, 10 

Nitrites,  31,  36,37 
Nitrobenzene,  170 
Nitrogen,  8, 10 

Oxides  of ,  10 

Nitroglycerin,  dosage,  166 
N  itrohydrochloric  acid,  160 
Nitrous  acid,  10 

anhydride,  10 
oxide,  10 
Non-metals,  9 

12 


Normal  acid  solutions,  59,  62,  63 

alkali  solutions,  59,  150,  <il 
Nucleo-albumins,  76,  81 
Nux  vomica,  see  Strychnine. 
Ny lander's  reagent,  160 
test,  109 

Oils,  84,  86 
Oleic  acid,  84 
Olein,  84 
Olive  oil,  86 
Opium,  170 
Orthophosphates,  34 
Osmium,  8 
Ossein,  76 
Oxalates,  35,  36,  39 

in  urine,  126, 127 
Oxalic  acid,  35,  36, 160, 171 
Oxides,  37,  40 
Oxygen,  8,  9 
Oxyha3moglobin,  93 
Ozone,  9 

Palladium,  8 
Palmitic  acid,  84 
Palmitin,  84 
Pancreatic  Fluid,  135 
Papain,  88 
Papaverine,  56 
Paraglobulin,  79 
Pavy's  solution,  163 
test,  70, 110 
Pentose,  121 
Pepsin,  88, 133 
Peptones,  76,  80,  82 

in  urine,  120 
Peptotoxin,  87 
Permanganates,  33,  37 
Permanganic  acid,  33 
Peroxides,  37 
Pettenkofer's  test,  118, 137 
Phenol,  40,  46,  55, 168 
Phenolphthalein,  59, 163 
Phenolsulphonic  acid,  147 
Phenyl-hydrazin  test,  71,  109 
Phosphates,  34,  37,  39, 116 

in  urine,  115, 126, 127 
Phosphites,  34 
Phosphoric  acid,  34, 160 
Phosphorus,  8, 11, 171 
Physostigmine,  55, 171 
Picric  acid,  46,  55, 160 

test  for  albumin,  78, 106 
Picric  acid,  test  for  dextrose,  70 
Picrotoxin,  55, 171 
Pilocarpine,  171 
Piotrowski's  reaction,  77 
Piperine,  55 
Platinic  chloride,  163 
Platinum,  8,  23 
Poikilocytosis,  95 


178 


INDEX. 


Poisons  and  Treatment,  165, 166 
Polysaccharids,  69 
Populin,  55 
Potassium,  8, 14 

bromide,  dosage,  166 

carbonate,  15 

hydroxide,  15 

salts  as   reagents,  163, 

164 

Poisoning  by,  171 
Praseodidymium,  8 
Proteids,  76,  77,  82 
Protein  reactions,  77 
Proteolytic  ferments,  88 
Prote9s'es,  76,  80 
Prussic  acid,  171 
Ptomaines,  53,  87 
Ptyalin,  88,  130 
Purdy's  solution,  164 

test,  70,  110 
Purple  of  Cassius,  23 
Pus  in  urine,  121,  124 
Putrescine,  53, 87 
Pyrogallates,  40 
Pyrophosphates,  34 
Pyroxylin,  73 

Qnantivalence  of  elements,  8 
Quinine,  51,  55,  65 

sulphate,  51 

Raffinose,  69 
Reagents,  List  of,  160 
Reinsch's  test,  42 
Rhodium,  8 
Ricinolein,  86 
Roberts'  test,  110 
Rosenbach's  test  for  bile,  117 
Rubidium,  8 
Ruthenium,  8 

Saccharic  acid,  69 

Salicin,  53,  56 

Salicylates,  35,  40, 143 

Salicylic  acid,  35, 160 

Saliva,  130 

Salkowski's  test  for  cholesterol,  138 

Samarium,  8 

Santonin,  55 

Sapo,  85 

mollis,  85 
Saponification,  85 
Saponin, 55 
Scandium,  8 
Schiff's  reagent,  164 
Schmiedeberg's  test,  70 
Selenium,  8 
Serum  albumin,  76,  79 

globulin,  76,  79, 119 
Silica,  13,  38 
Silicates,  13,  37,  38 


Silicic  acids,  13 
Silicon,  8, 13 
Silver,  8, 24 

nitrate,  164, 171 
Snake  poisons,  171 
Soap  tests,  85 
Sodium,  8, 15 

carbonate,  15 
hydroxide,  15 
pyroborate,  32 
salts  as  reagents,  164 
tetraborate,  32 
Solanine,  56, 171 
Solubilities,  Table  of,  158 
Sorbose,  69 
Sparteine,  48,  55,  65 
Special  tests,  41 
Spermatozoa  in  urine,  125 
Spermirie,  53 
Standard  solutions,  58 
Stannic  compounds,  23 
Stannous  compounds,  23 

chloride,  164 
Starch,  69,  73 
Stas-Otto  method,  54 
Steapsin,  88, 135 
Stearic  acid,  84 
Stearin,  84 

Steatolytic  ferments,  87 
Stramonium,  Poisoning  by,  172 
Strontium,  8, 16 

nitrate,  164 
Strychnine,  52,  55,  65,  172 

sulphate,  52, 166 
Succinates,  37,  40 
Sucrose,  69,  71 
Sugar  in  urine,  107 

Quantitative  test  for,  109 
Sugars,  36, 69 
Sulphanilic  acid,  148 
Sulphates,  31,  37,  39 

in  urine,  114, 115 
Sulphides,  31,  36,  37 
Sulphites,  31,  36,  37 
Sulphocyanates,  39,  40 
Sulphur,  8, 12,  37,  38 

in  albumin,  79 
Oxides  of,  12 

Sulphuretted  hydrogen,  164 
Sulphuric  acid,  12,  31,  160 
Sulphurous  acid,  12 
Sweat,  129 
Symbols  of  elements,  8 

Tannates,  40 
Tannic  acid,  160, 166 
test,  78 
Tantalum,  8 
Tanret's  solution,  164 

test,  78 
Tartar  emetic,  172 


INDEX. 


179 


Tartaric  acid,  36,  37, 160 
Tartrates,  36,  39 
Taurin,  137 
Taurocholic  acid,  137 
Tellurium,  8 

Temperature,  Measures  of,  157 
Terbium,  8 
Tetraboric  acid,  13 
Thallium,  8 
Thebaine,  55 
Theine,  49 
Theobromine,  55 
Thiosulphates,  31,36 
Thorium,  8 

Thrombin,  76,  81,88,92 
Thulium,  8 
Tin,  8,  23,  37 
Titanium,  8 
Toxalbumins,  87 
-Toxins,  87 

Trapp's  coefficient,  104 
Trichloracetic  acid,  160 

test,  78 

Trommer's  test,  70, 108 
Trypsin,  88, 135 
Tungstates,  37 
Tungsten,  8 
Typhotoxine,  53 
Tyrosin,  126, 135 
Tyrotoxicon,  53 

Uffelmann's  reagent,  164 
test,  132 

Uranium,  8 

nitrate  solution,  116 

Urates  in  urine,  112, 126, 127 

Urea  in  urine,  110 

Ureameter,  112 

Uric  acid  in  urine,  112, 126,  127 

Urinary  calculi,  127 

sediments,  123 

Urine,  Acetone  in,  120 

Acetylacetic  acid  in.  120 
Acidity  of,  102 
Albumin  in,  104 
Albumose  in,  119 
Alkaloids  in,  122 
Bacteria  in,  125 
Bile  in,  117 
Blood  in,  118, 124 
Carbonates  in,  126 
Casts  in,  124 
Chlorides  in,  113 
Color  of,  101 
Composition  of,  99 
Cystin  in,  127, 128 
Dextrose  in,  107 
Diacetic  acid  in,  120 


Urine,  Diazo-reaction  with,  122 

Drugs  in,  122 

Epithelium  in,  124 

Fat  in,  121 

Fungi  in,  125 

Glycuronic  acid  in,  121 

Gonococci  in,  125 

Hydroxybutyric  acid  in,  121 

Indican  in,  117 

Leucin  in,  126 

Mucin  in,  104, 124 

Oxalates  in,  126, 127 

Peptones  in,  120 

Phosphates  in,  115, 126, 127 

Plan  of  analysis  of,  100 

Pus  in,  121, 124 

Quantity  of,  100 

Reaction  of,  101 

Serum-globulin  in,  119 

Solids  of,  99, 103 

Specific  gravity  of,  102 

Spermatozoa  in,  125 

Sugar  in,  107 

Sulphates  in,  114 

Tyrosin  in,  126 

Urates  in,  112, 126,  127 

Urea  in,  110 

Uric  acid  in,  112, 126, 127 
Urinometer,  103 

Valence  of  elements,  8 
Vanadium,  8 
Veratrine,  52,  55, 172 
Veratrum,  Poisoning  by,  172 
Vitellin,  76,  81,  82 
Volumetric  Analysis,  57 

Water,  9 

Analysis  of,  145 
Clinical  tests,  149 
Examples  of  analyses,  151 
Interpretation  of  results,  149 

Weight,  Measures  of,  155 

Werner-Schmid  method  for  fat,  142 

Whey,  140 

Xanthine,  53, 127, 128 
Xanthocreatinine,  53 
Xanthoproteic  reaction,  77 

Ytterbium,  8 
Yttrium,  8 

z'inc,  8, 19,  37 

Zinc  salts  as  poisons,  172 

sulphate,  dosage,  166 
Zirconium,  8 


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QD83   Platt,  C.        47578 

P71      I/anual  of  qualitative  anal- 

1900     ysis~.  3d  ed. 


